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Ryo Funada - One of the best experts on this subject based on the ideXlab platform.
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responses of ray parenchyma cells to wounding differ between Earlywood and latewood in the sapwood of cryptomeria japonica
Trees-structure and Function, 2017Co-Authors: Satoshi Nakaba, Yusuke Yamagishi, Hikaru Morimoto, Izumi Arakawa, Ryogo Nakada, Ryo FunadaAbstract:Changes in cellular contents of ray parenchyma cells during the formation of reaction zone differ between Earlywood and latewood in the sapwood of Cryptomeria japonica. Changes over time in the cellular contents of xylem parenchyma cells provide important clues to the mechanism of the early events in the wound reaction of trees. In this study, we monitored the events that occur during the death of ray parenchyma cells after wounding. We examined nuclei, starch grains, and colored substances in ray parenchyma cells by light microscopy and the autofluorescence of cell walls of tracheids by confocal laser-scanning microscopy in Cryptomeria japonica after artificial wounding. In addition, we compared cytological changes in ray parenchyma cells in the longitudinal and radial directions. Finally, we analyzed the differences between Earlywood and latewood in terms of the responses of ray parenchyma cells to wounding. Behind the wound, changes in cellular contents were visible first in latewood regions in the second annual ring behind the wound. The progression of changes in cellular contents of ray parenchyma cells stopped near the growth-ring boundary. These results indicate that the growth-ring boundary might prevent the spread of some factor(s) that induces cytological changes in ray parenchyma cells. Above the wound, most colored substances were localized in ray parenchyma cells that were located near wounds in latewood regions. Thus, even at an equal distance from the wound, the amount of secondary metabolites in ray parenchyma cells differed between Earlywood and latewood. Our observations suggest that differences in the anatomical features of neighboring tracheids between Earlywood and latewood might influence changes in cellular contents of ray parenchyma cells during reactions to wounding in Cryptomeria japonica.
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Relationship between formation of Earlywood vessels and leaf phenology in two ring-porous hardwoods, Quercus serrata and Robinia pseudoacacia, in early spring
Journal of Wood Science, 2015Co-Authors: Kayo Kudo, Koh Yasue, Yoshihiro Hosoo, Ryo FunadaAbstract:In deciduous ring-porous hardwoods, three-dimensional networks of the current year’s Earlywood vessels play an important role in the movement of water. In the present study, we analyzed the formation of Earlywood vessels along the main stem and leaf phenology in two deciduous ring-porous hardwoods, Quercus serrata and Robinia pseudoacacia . We introduced a dye in an effort to monitor the timing of initial water conduction through the network of the current year’s Earlywood vessels. The formation of Earlywood vessels began before bud break. At bud break, perforation of the first Earlywood vessels was evident at the top of the stem but not at other positions within the stem. Perforations were observed along the entire stem when small leaves became visible and then leaves continued to develop. These results suggest that conduction of water via the network of the first Earlywood vessels of the current year might not contribute to the initial growth of buds but might play an important role in the development of the current year’s leaves and shoots.
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changes in radial growth of Earlywood in quercus crispula between 1970 and 2004 reflect climate change
Trees-structure and Function, 2015Co-Authors: Ryo Funada, Eri Nabeshima, Takuya Kubo, Koh Yasue, Tsutom HiuraAbstract:Earlywood width in Quercus crispula increased from 1970 to 2004 without changes of vessel anatomy and ring growth. The increase in diameter of a tree stem is an important indicator of forest productivity. Xylem traits, such as the number and cross-sectional area of Earlywood vessels, are also critical parameters of forest growth because of the physiological and structural contribution of xylem to the growth of the tree stem. Forest productivity appears to be affected by climate change and, indeed, trees might be expected to acclimate to gradual long-term climate change. The aim of this study was to identify long-term changes in increases in stem diameter and in Earlywood vessels by examining tree rings of Quercus crispula. Focusing on 20 mature specimens of Q. crispula, we examined annual ring growth from 1970 to 2004 and measured Earlywood traits, namely, the width, cross-sectional area (henceforth referred to as area) and number of Earlywood vessels, by digital image analysis. We developed a hierarchical Bayesian model for detection of long-term trends in these traits. We found that Earlywood width, as well as the total number and area of Earlywood vessels, increased during the 35 years under analysis. One possible cause of these changes might be the long-term elevation of temperatures in early spring, which determine the timing of the onset of cambial reactivation from winter dormancy. In contrast to the long-term changes, short-term, yearly changes in Earlywood traits fluctuated to a smaller extent than yearly changes in tree ring width. Therefore, the observed long-term changes in Earlywood appear to represent acclimation to long-term climate change.
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the effects of localized heating and disbudding on cambial reactivation and formation of Earlywood vessels in seedlings of the deciduous ring porous hardwood quercus serrata
Annals of Botany, 2014Co-Authors: Kayo Kudo, Eri Nabeshima, Koh Yasue, Yusuke Yamagishi, Satoshi Nakaba, Shahanara Begum, Yuichiro Oribe, Ryo FunadaAbstract:† Background and Aims The networks of vessel elements play a vital role in the transport of water from roots to leaves, and the continuous formation of Earlywood vessels is crucial for the growth of ring-porous hardwoods. The differentiation of Earlywood vessels is controlled by external and internal factors. The present study was designed to identify the limiting factors in the induction of cambial reactivation and the differentiation of Earlywood vessels, using localized heating and disbudding of dormant stems of seedlings of a deciduous ring-porous hardwood, Quercus serrata. † Methods Localized heating was achieved by wrapping an electric heating ribbon around stems. Disbudding involved removal of all buds. Three treatments were initiated on 1 February 2012, namely heating, disbudding and a combination of heating and disbudding, with untreated dormant stems as controls. Cambial reactivation and differentiation of vessel elements were monitored by light and polarized-light microscopy, and the growth of buds was followed. † Key Results Cambial reactivation and differentiation of vessel elements occurred sooner in heated seedlings than in non-heated seedlings before bud break. The combination of heating and disbudding of seedlings also resulted in earlier cambial reactivation and differentiation of first vessel elements than in non-heated seedlings. A few narrow vessel elements were formed during heating after disbudding, while many large Earlywood vessel elements were formed in heated seedlings with buds. † Conclusions The results suggested that, in seedlings of the deciduous ring-porous hardwood Quercus serrata, elevated temperature was a direct trigger for cambial reactivation and differentiation of first vessel elements. Bud growth was not essential for cambial reactivation and differentiation of first vessel elements, but might be important for the continuous formation of wide vessel elements.
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seasonal and perennial changes in the distribution of water in the sapwood of conifers in a sub frigid zone
Plant Physiology, 2003Co-Authors: Yasuhiro Utsumi, Yuzou Sano, Ryo Funada, Jun Ohtani, Seizo FujikawaAbstract:An analysis was made of progressive changes in patterns of cavitation in the sapwood of three species of conifer (Larix kaempferi, Abies sachalinensis, and Picea jezoensis) that were growing in a sub-frigid zone. In all three conifers, all tracheids of the newly forming outermost annual ring were filled with water or cytoplasm during the period from May to August. However, many tracheids in the transition zone from Earlywood to latewood lost water in September, presumably through drought-induced cavitation. Cavitated tracheids tended to be continuously distributed in a tangential direction. Subsequently, some Earlywood tracheids of the outermost annual ring lost water during the period from January to March. This was associated with freeze-thaw cycles. In the second and third annual rings from the cambium of all three conifers, the lumina of most tracheids in the transition zone from Earlywood to latewood contained no water. In contrast, some latewood tracheids near the annual ring boundary and many Earlywood tracheids retained water in their lumina. The third annual ring had more cavitated tracheids than the second annual ring. Our observations indicated that cavitation progressed gradually in the tracheids of the conifers and that they were never refilled once cavitation had occurred. The region involved in water transport in conifers did not include the entire sapwood and differed among annual rings.
Ignacio Garciagonzalez - One of the best experts on this subject based on the ideXlab platform.
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chronologies of Earlywood vessels and latewood width disentangle climate drivers of oak growth in a mild oceanic region
Dendrochronologia, 2018Co-Authors: Manuel Soutoherrero, Vicente Rozas, Ignacio GarciagonzalezAbstract:Abstract We obtained tree-ring chronologies for pedunculate oak along an altitudinal gradient of four sites in NW Iberia, which covers most of the species range within the region. Trees grow under Atlantic climate, with a rainfall maximum in autumn-winter, and a minimum during summer, but lacking a remarkable drought. Chronologies included several Earlywood anatomical features and ring widths, which were compared to each other. Latewood width and a subset of six Earlywood variables were selected for further analyses, considering the period 1954–2003. The lowest site considerably differed from the rest of the gradient due to its milder conditions. Earlywood and latewood were unrelated at the three upper sites, and both compartments responded to different climatic factors. Hydraulic conductivity determined by vessel size was used to describe tree performance, which was modulated by temperature along the gradient. We hypothesize that the main processes involved are the timing of Earlywood formation and carbohydrate dynamics. Water availability during late spring and summer affected latewood width, but only at low elevation. This paper illustrates the complexity of analyzing climate-growth relationships in oceanic areas under the absence of a prevailing limiting factor, while providing a feasible explanation of potential mechanisms involved.
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a 481 year chronology of oak Earlywood vessels as an age independent climatic proxy in nw iberia
Global and Planetary Change, 2017Co-Authors: Manuel Soutoherrero, Vicente Rozas, Ignacio GarciagonzalezAbstract:Abstract The Earlywood vessels of ring-porous trees can be analyzed dendrochronologically and used as a proxy for environmental information. However, most works deal with the analysis of contemporary climate-growth relationships and do not evaluate their long-term variation. We obtained a 481-year chronology of Earlywood vessel size of oak ( Quercus robur L.) in the northwestern Iberian Peninsula, investigated its behavior through time, and compared it to a chronology of younger trees developed at the same site. We expressed Earlywood vessel size as the hydraulically-weighted diameter ( D H ) and discriminated between vessels in the first row ( r1 ) and the rest of the vessels ( nr1 ); radial increment was assessed from latewood width (LW). Climate-growth relationships were strong and nearly identical for both age classes. Spring temperature positively affected vessel size, but only for the first row, probably mediating the onset of cambial activity. The chronology of old trees showed an almost flat age trend, except for the first decades, and series were not affected by stand dynamics. In contrast, LW had a weak response to climate, probably because of the high impact of abrupt growth changes. There was a high negative correlation between D H and the winter North Atlantic Oscillation Index (NAO), which was unstable during the 20th century. To our knowledge, this is the longest chronology of Earlywood vessel size obtained to date, and offers promising results, as this proxy is shown to be independent of age and forest disturbances, and was strongly correlated to climate across long time spans.
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ring porosity and Earlywood vessels a review on extracting environmental information through time
Iawa Journal, 2016Co-Authors: Ignacio Garciagonzalez, Manuel Soutoherrero, Filipe CampeloAbstract:Many anatomical features in trees result from their reaction to fluctuating environmental conditions, and some can be measured and dated. Recently, quantitative wood anatomy has been used to build time series, and consequently to study the responses of trees through time. This involves the application of dendrochronological techniques, although some methodological adaptations are necessary when using anatomical variables. Until now, the study of continuous anatomical series has proven to be very promising when applied to the Earlywood vessels of ring-porous trees, due to their great physiological relevance.In this paper, we review the main aspects that must be considered when building continuous series of Earlywood vessel features of ring-porous trees as compared to ‘classical’ dendrochronology. We first discuss the procedures for building individual series and chronologies, starting with the selection of variables, examining their statistical properties, and assessing how crossdating and detrending should be adapted. We also show that time series of Earlywood vessels usually exhibit a low common signal, but in contrast are strongly related to climate, and often reveal responses not recorded by the classical dendrochronological variables.In addition, we deal with the optimization of environmental signals, by first evaluating multiple potential variables to be used, and indicate how to reduce their number according to the relations among them. As Earlywood variables are basically determined by vessel number or vessel size, we discuss the search for the most appropriate variable to characterize vessel number, as well as the advantage of progressively selecting Earlywood vessels attending to their size and position.Finally, we extend the application of these methodologies to diffuse-porous species as compared to ring-porous trees, and show that the climatic signal contained in their anatomical features is also relevant, provided that vessels are carefully selected upon their location within the ring.
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effects of climate on Earlywood vessel formation of quercus robur and q pyrenaica at a site in the northwestern iberian peninsula
Canadian Journal of Forest Research, 2015Co-Authors: Borja D Gonzalezgonzalez, Rosa Ana Vazquezruiz, Ignacio GarciagonzalezAbstract:We analysed climate–growth relationships for two ring-porous oak species (Quercus robur L. and Q. pyrenaica Willd.) at one site in northwestern Spain. Increment cores from 12 living trees per species were taken for ring and Earlywood vessel measurements, considering three width variables (for Earlywood, latewood, and the whole ring) and six anatomical variables (based on vessel area distribution, number of vessels, and conductivity) in the Earlywood. We used standard dendrochronological procedures and compared each mean series with meteorological records of temperature, precipitation, and estimates of soil water content. Earlywood width was negatively related to precipitation in the previous late season for Q. robur, but it was controlled by the previous spring temperature for Q. pyrenaica. These responses were highly dependent on vessel number and probably related to carbohydrate storage dynamics but differed between species. Vessel size showed a stronger relationship to climate and was mainly coupled to...
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Earlywood vessels of the sub mediterranean oak quercus pyrenaica have greater plasticity and sensitivity than those of the temperate q petraea at the atlantic mediterranean boundary
Trees-structure and Function, 2014Co-Authors: Borja D Gonzalezgonzalez, Vicente Rozas, Ignacio GarciagonzalezAbstract:Earlywood vessel features indicate different adaptations of Quercus petraea and Q. pyrenaica , which are probably related with their corresponding Atlantic and sub-Mediterranean ecological requirements. We studied the climatic signal of the Earlywood anatomy of a temperate [Quercus petraea (Mattuschka) Liebl.] and a sub-Mediterranean (Quercus pyrenaica Willd.) oak species growing under similar climatic conditions in a transitional area between the Atlantic and Mediterranean regions of the Iberian Peninsula. We hypothesized that both species react differently in their wood anatomy due to their contrasting ecological requirements, and we test the usefulness of Earlywood anatomical features to study the behaviour of these ring-porous oaks upon climate. For this, we measured the Earlywood vessels, and obtained annual series of several anatomical variables for the period 1937–2006 using dendrochronological techniques, considering whether the vessels belonged to the first row or not. After optimizing the data set by principal component analysis and progressive filtering of large vessels, we selected maximum vessel area and total number of vessels as they resulted to be the optimal variables to describe vessel size and number, respectively. Vessel size of Q. pyrenaica was dependent on precipitation along the previous growing season, whereas it did not show any clear climatic response for Q. petraea. On the contrary, vessel number was related to winter temperature for both species. These relationships observed between climate and anatomy appeared to be stable through time. The results obtained reinforce the utility of Earlywood vessel features as potential climate proxies.
Eri Nabeshima - One of the best experts on this subject based on the ideXlab platform.
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formation of new networks of Earlywood vessels in seedlings of the deciduous ring porous hardwood quercus serrata in springtime
Trees-structure and Function, 2018Co-Authors: Yasuhiro Utsumi, Eri Nabeshima, Kayo Kudo, Katsushi Kuroda, Yusuke Yamagishi, Satoshi Nakaba, Koh YasueAbstract:Complete differentiation of the first Earlywood vessels occurred earlier in upper regions of stems than in middle and lower regions when buds swelling in a ring-porous hardwood Quercus serrata seedlings. In deciduous ring-porous hardwoods, the timing of the onset of conduction of water via the networks of the current year’s Earlywood vessels is very important for the growth of buds and shoots because the main pathways for conduction of water are the networks of the current year’s Earlywood vessels. The purpose of this study was to visualize the formation of the networks of first Earlywood vessels in the current year’s xylem of seedlings of the deciduous ring-porous hardwood Quercus serrata. We monitored the distribution of water in the current and the previous year’s secondary xylem at the cellular level in upper, middle and lower regions of stems during the formation of Earlywood vessels by cryo-scanning electron microscopy after freeze-etching. We also examined how changes in water distribution were correlated with leaf phenology. The contents of the first vessel elements in the upper region of the stem changed from cytoplasm-rich to water earlier than those in middle and lower regions of the stem when buds were increasing in size. At bud break, vessel elements were filled with water throughout the entire stem. When the cambium was dormant and during formation of Earlywood vessels, the previous year’s latewood vessels were filled with water. Our results showed that complete differentiation of vessel elements occurred earlier in upper regions of stems than in middle and lower regions. Moreover, the functional networks of the previous year’s latewood vessels appeared to be involved in supplying water to new networks of Earlywood vessels in the current year’s xylem.
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changes in radial growth of Earlywood in quercus crispula between 1970 and 2004 reflect climate change
Trees-structure and Function, 2015Co-Authors: Ryo Funada, Eri Nabeshima, Takuya Kubo, Koh Yasue, Tsutom HiuraAbstract:Earlywood width in Quercus crispula increased from 1970 to 2004 without changes of vessel anatomy and ring growth. The increase in diameter of a tree stem is an important indicator of forest productivity. Xylem traits, such as the number and cross-sectional area of Earlywood vessels, are also critical parameters of forest growth because of the physiological and structural contribution of xylem to the growth of the tree stem. Forest productivity appears to be affected by climate change and, indeed, trees might be expected to acclimate to gradual long-term climate change. The aim of this study was to identify long-term changes in increases in stem diameter and in Earlywood vessels by examining tree rings of Quercus crispula. Focusing on 20 mature specimens of Q. crispula, we examined annual ring growth from 1970 to 2004 and measured Earlywood traits, namely, the width, cross-sectional area (henceforth referred to as area) and number of Earlywood vessels, by digital image analysis. We developed a hierarchical Bayesian model for detection of long-term trends in these traits. We found that Earlywood width, as well as the total number and area of Earlywood vessels, increased during the 35 years under analysis. One possible cause of these changes might be the long-term elevation of temperatures in early spring, which determine the timing of the onset of cambial reactivation from winter dormancy. In contrast to the long-term changes, short-term, yearly changes in Earlywood traits fluctuated to a smaller extent than yearly changes in tree ring width. Therefore, the observed long-term changes in Earlywood appear to represent acclimation to long-term climate change.
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the effects of localized heating and disbudding on cambial reactivation and formation of Earlywood vessels in seedlings of the deciduous ring porous hardwood quercus serrata
Annals of Botany, 2014Co-Authors: Kayo Kudo, Eri Nabeshima, Koh Yasue, Yusuke Yamagishi, Satoshi Nakaba, Shahanara Begum, Yuichiro Oribe, Ryo FunadaAbstract:† Background and Aims The networks of vessel elements play a vital role in the transport of water from roots to leaves, and the continuous formation of Earlywood vessels is crucial for the growth of ring-porous hardwoods. The differentiation of Earlywood vessels is controlled by external and internal factors. The present study was designed to identify the limiting factors in the induction of cambial reactivation and the differentiation of Earlywood vessels, using localized heating and disbudding of dormant stems of seedlings of a deciduous ring-porous hardwood, Quercus serrata. † Methods Localized heating was achieved by wrapping an electric heating ribbon around stems. Disbudding involved removal of all buds. Three treatments were initiated on 1 February 2012, namely heating, disbudding and a combination of heating and disbudding, with untreated dormant stems as controls. Cambial reactivation and differentiation of vessel elements were monitored by light and polarized-light microscopy, and the growth of buds was followed. † Key Results Cambial reactivation and differentiation of vessel elements occurred sooner in heated seedlings than in non-heated seedlings before bud break. The combination of heating and disbudding of seedlings also resulted in earlier cambial reactivation and differentiation of first vessel elements than in non-heated seedlings. A few narrow vessel elements were formed during heating after disbudding, while many large Earlywood vessel elements were formed in heated seedlings with buds. † Conclusions The results suggested that, in seedlings of the deciduous ring-porous hardwood Quercus serrata, elevated temperature was a direct trigger for cambial reactivation and differentiation of first vessel elements. Bud growth was not essential for cambial reactivation and differentiation of first vessel elements, but might be important for the continuous formation of wide vessel elements.
Kayo Kudo - One of the best experts on this subject based on the ideXlab platform.
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formation of new networks of Earlywood vessels in seedlings of the deciduous ring porous hardwood quercus serrata in springtime
Trees-structure and Function, 2018Co-Authors: Yasuhiro Utsumi, Eri Nabeshima, Kayo Kudo, Katsushi Kuroda, Yusuke Yamagishi, Satoshi Nakaba, Koh YasueAbstract:Complete differentiation of the first Earlywood vessels occurred earlier in upper regions of stems than in middle and lower regions when buds swelling in a ring-porous hardwood Quercus serrata seedlings. In deciduous ring-porous hardwoods, the timing of the onset of conduction of water via the networks of the current year’s Earlywood vessels is very important for the growth of buds and shoots because the main pathways for conduction of water are the networks of the current year’s Earlywood vessels. The purpose of this study was to visualize the formation of the networks of first Earlywood vessels in the current year’s xylem of seedlings of the deciduous ring-porous hardwood Quercus serrata. We monitored the distribution of water in the current and the previous year’s secondary xylem at the cellular level in upper, middle and lower regions of stems during the formation of Earlywood vessels by cryo-scanning electron microscopy after freeze-etching. We also examined how changes in water distribution were correlated with leaf phenology. The contents of the first vessel elements in the upper region of the stem changed from cytoplasm-rich to water earlier than those in middle and lower regions of the stem when buds were increasing in size. At bud break, vessel elements were filled with water throughout the entire stem. When the cambium was dormant and during formation of Earlywood vessels, the previous year’s latewood vessels were filled with water. Our results showed that complete differentiation of vessel elements occurred earlier in upper regions of stems than in middle and lower regions. Moreover, the functional networks of the previous year’s latewood vessels appeared to be involved in supplying water to new networks of Earlywood vessels in the current year’s xylem.
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Relationship between formation of Earlywood vessels and leaf phenology in two ring-porous hardwoods, Quercus serrata and Robinia pseudoacacia, in early spring
Journal of Wood Science, 2015Co-Authors: Kayo Kudo, Koh Yasue, Yoshihiro Hosoo, Ryo FunadaAbstract:In deciduous ring-porous hardwoods, three-dimensional networks of the current year’s Earlywood vessels play an important role in the movement of water. In the present study, we analyzed the formation of Earlywood vessels along the main stem and leaf phenology in two deciduous ring-porous hardwoods, Quercus serrata and Robinia pseudoacacia . We introduced a dye in an effort to monitor the timing of initial water conduction through the network of the current year’s Earlywood vessels. The formation of Earlywood vessels began before bud break. At bud break, perforation of the first Earlywood vessels was evident at the top of the stem but not at other positions within the stem. Perforations were observed along the entire stem when small leaves became visible and then leaves continued to develop. These results suggest that conduction of water via the network of the first Earlywood vessels of the current year might not contribute to the initial growth of buds but might play an important role in the development of the current year’s leaves and shoots.
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the effects of localized heating and disbudding on cambial reactivation and formation of Earlywood vessels in seedlings of the deciduous ring porous hardwood quercus serrata
Annals of Botany, 2014Co-Authors: Kayo Kudo, Eri Nabeshima, Koh Yasue, Yusuke Yamagishi, Satoshi Nakaba, Shahanara Begum, Yuichiro Oribe, Ryo FunadaAbstract:† Background and Aims The networks of vessel elements play a vital role in the transport of water from roots to leaves, and the continuous formation of Earlywood vessels is crucial for the growth of ring-porous hardwoods. The differentiation of Earlywood vessels is controlled by external and internal factors. The present study was designed to identify the limiting factors in the induction of cambial reactivation and the differentiation of Earlywood vessels, using localized heating and disbudding of dormant stems of seedlings of a deciduous ring-porous hardwood, Quercus serrata. † Methods Localized heating was achieved by wrapping an electric heating ribbon around stems. Disbudding involved removal of all buds. Three treatments were initiated on 1 February 2012, namely heating, disbudding and a combination of heating and disbudding, with untreated dormant stems as controls. Cambial reactivation and differentiation of vessel elements were monitored by light and polarized-light microscopy, and the growth of buds was followed. † Key Results Cambial reactivation and differentiation of vessel elements occurred sooner in heated seedlings than in non-heated seedlings before bud break. The combination of heating and disbudding of seedlings also resulted in earlier cambial reactivation and differentiation of first vessel elements than in non-heated seedlings. A few narrow vessel elements were formed during heating after disbudding, while many large Earlywood vessel elements were formed in heated seedlings with buds. † Conclusions The results suggested that, in seedlings of the deciduous ring-porous hardwood Quercus serrata, elevated temperature was a direct trigger for cambial reactivation and differentiation of first vessel elements. Bud growth was not essential for cambial reactivation and differentiation of first vessel elements, but might be important for the continuous formation of wide vessel elements.
Yasuhiro Utsumi - One of the best experts on this subject based on the ideXlab platform.
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formation of new networks of Earlywood vessels in seedlings of the deciduous ring porous hardwood quercus serrata in springtime
Trees-structure and Function, 2018Co-Authors: Yasuhiro Utsumi, Eri Nabeshima, Kayo Kudo, Katsushi Kuroda, Yusuke Yamagishi, Satoshi Nakaba, Koh YasueAbstract:Complete differentiation of the first Earlywood vessels occurred earlier in upper regions of stems than in middle and lower regions when buds swelling in a ring-porous hardwood Quercus serrata seedlings. In deciduous ring-porous hardwoods, the timing of the onset of conduction of water via the networks of the current year’s Earlywood vessels is very important for the growth of buds and shoots because the main pathways for conduction of water are the networks of the current year’s Earlywood vessels. The purpose of this study was to visualize the formation of the networks of first Earlywood vessels in the current year’s xylem of seedlings of the deciduous ring-porous hardwood Quercus serrata. We monitored the distribution of water in the current and the previous year’s secondary xylem at the cellular level in upper, middle and lower regions of stems during the formation of Earlywood vessels by cryo-scanning electron microscopy after freeze-etching. We also examined how changes in water distribution were correlated with leaf phenology. The contents of the first vessel elements in the upper region of the stem changed from cytoplasm-rich to water earlier than those in middle and lower regions of the stem when buds were increasing in size. At bud break, vessel elements were filled with water throughout the entire stem. When the cambium was dormant and during formation of Earlywood vessels, the previous year’s latewood vessels were filled with water. Our results showed that complete differentiation of vessel elements occurred earlier in upper regions of stems than in middle and lower regions. Moreover, the functional networks of the previous year’s latewood vessels appeared to be involved in supplying water to new networks of Earlywood vessels in the current year’s xylem.
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seasonal and perennial changes in the distribution of water in the sapwood of conifers in a sub frigid zone
Plant Physiology, 2003Co-Authors: Yasuhiro Utsumi, Yuzou Sano, Ryo Funada, Jun Ohtani, Seizo FujikawaAbstract:An analysis was made of progressive changes in patterns of cavitation in the sapwood of three species of conifer (Larix kaempferi, Abies sachalinensis, and Picea jezoensis) that were growing in a sub-frigid zone. In all three conifers, all tracheids of the newly forming outermost annual ring were filled with water or cytoplasm during the period from May to August. However, many tracheids in the transition zone from Earlywood to latewood lost water in September, presumably through drought-induced cavitation. Cavitated tracheids tended to be continuously distributed in a tangential direction. Subsequently, some Earlywood tracheids of the outermost annual ring lost water during the period from January to March. This was associated with freeze-thaw cycles. In the second and third annual rings from the cambium of all three conifers, the lumina of most tracheids in the transition zone from Earlywood to latewood contained no water. In contrast, some latewood tracheids near the annual ring boundary and many Earlywood tracheids retained water in their lumina. The third annual ring had more cavitated tracheids than the second annual ring. Our observations indicated that cavitation progressed gradually in the tracheids of the conifers and that they were never refilled once cavitation had occurred. The region involved in water transport in conifers did not include the entire sapwood and differed among annual rings.
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the progression of cavitation in Earlywood vessels of fraxinus mandshurica var japonica during freezing and thawing
Plant Physiology, 1999Co-Authors: Yasuhiro Utsumi, Seizo Fujikawa, Yuzou Sano, Ryo Funada, Jun OhtaniAbstract:For an examination of the progression of cavitation in large-diameter Earlywood vessels of a deciduous ring-porous tree, potted saplings of Fraxinus mandshurica var japonica Maxim. were frozen and then thawed. The changes in the amount and distribution of water in the lumina of the current year's Earlywood vessels during the course of the freezing and thawing were visualized by cryo-scanning electron microscopy. When samples were frozen, most of the current year's Earlywood vessels were filled with water. After the subsequent thawing, the percentage of cavitated current-year Earlywood vessels gradually increased with time. All of the current year's Earlywood vessels were cavitated within 24 h, and only limited amounts of water remained in the lumina of Earlywood vessels. Similar cavitation of Earlywood vessels was observed after thawing of frozen, excised stem pieces. In contrast, many vessels of the current year's latewood retained water in the lumina during freezing and thawing. These observations indicate that the cavitation of the current year's Earlywood vessels is not produced during freezing but progresses during rewarming after freezing in F. mandshurica var japonica.
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seasonal changes in the distribution of water in the outer growth rings of fraxinus mandshurica var japonica a study by cryo scanning electron microscopy
Iawa Journal, 1996Co-Authors: Yasuhiro Utsumi, Yuzou Sano, Jun Ohtani, Seizo FujikawaAbstract:Seasonal changes in the distribution of water in the outer growth rings of Fraxinus mandshurica var.japonica were visualised by cryo-scanning electron microscopy using samples in which water was freeze-fixed in the living trunk . During the growing season from mid-May to late-July when formation ofxylem progressed steadily, all cell lumina of the newly forming xylem elements were filled with water. From August to October, water was lost from the lumina of wood fibres in the current-year xylem. Loss of water from wood fibres began in August at the initial zone of the Earlywood, and progressed toward the cambial zone. By November, water had disappeared from the lumina of current-year Earlywood vessels, and water reappeared in the lumina of Earlywood fibres around the currentyear Earlywood vessels. Our results indicate that cavitation in lumina of current-year Earlywood vessels occurred during the period from October to November.
