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T. K. Roy - One of the best experts on this subject based on the ideXlab platform.

  • Do seed VLCFAs trigger Spongy Tissue formation in Alphonso mango by inducing germination
    Journal of biosciences, 2015
    Co-Authors: S. Shivashankar, Manoharan Sumathi, T. K. Roy
    Abstract:

    Spongy Tissue is a physiological disorder in Alphonso mango caused by the inception of germination-associated events during fruit maturation on the tree, rendering the fruit inedible. Inter-fruit competition during active fruit growth is a major contributing factor for the disorder which leads to reduced fat content in Spongy Tissue affected fruits. This study was, therefore, carried out to determine the possible association between seed fats and ST formation. The study of the fat content during fruit growth showed that it increased gradually from 40% fruit maturity. At 70% maturity, however, there was a sudden increase of fat content of whole fruit, leading to acute competition and resulting in differential allocation of resources among developing fruits. As a result, the seed in Spongy-Tissue-affected mature ripe fruit showed a marked drop in the levels of fats and the two very long chain fatty acids (VLCFAs), tetracosanoic acid and hexacosanoic acid together with an increase of linolenic acid and a fall in oleic acid contents, which are known to be key determinants for the initiation of pre-germination events in seed. Subsequently, a rise in the level of cytokinin and gibberellins in ST seed associated with a fall in abscisic acid level clearly signalled the onset of germination. Concurrently, a significant reduction in the ratio of linolenic acid/linoleic acid in pulp led to the loss of membrane integrity, cell death and the eventual formation of Spongy Tissue. Based on the above, it is concluded that a significant reduction in the biosynthesis of VLCFAs in seeds during fruit growth might trigger pre-germination events followed by a cascade of biochemical changes in the pulp, leading to lipid peroxidation and membrane injury in pulp culminating in ST development. Thus, this study presents crucial experimental evidence to highlight the critical role played by VLCFAs in inducing ST formation in Alphonso mango during the pre-harvest phase of fruit growth.

  • Role of oxidative stress and the activity of ethylene biosynthetic enzymes on the formation of Spongy Tissue in ‘Alphonso’ mango
    Journal of food science and technology, 2010
    Co-Authors: J. E. Nagamani, K. S. Shivashankara, T. K. Roy
    Abstract:

    Spongy Tissue formation in ‘Alphonso’ mangoes (Mangifera indica L) is a major national problem leading to loss for farmers and traders. Spongy Tissue is whitish sponge like Tissue formed near the seed with insipid taste and off odour. Lipid peroxidation of membranes as studied by malondialdehyde formation was significantly higher in Spongy Tissue. Activities of antioxidative enzymes like superoxide dismutase, catalase, peroxidase and polyphenol oxidase were lower in Spongy Tissue. Among the antioxidative enzymes, activities of catalase and peroxidases were severely reduced leading to membrane damage in Spongy Tissue. A significant reduction in 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase and accumulation of ACC was also observed in Spongy Tissue. However, ACC synthase activity in Spongy Tissue was more compared to healthy Tissue. Results indicate that the membrane peroxidation leading to lower activity of ACC oxidase might lead to the formation of Spongy Tissue in ‘Alphonso’ mango.

  • role of oxidative stress and the activity of ethylene biosynthetic enzymes on the formation of Spongy Tissue in alphonso mango
    Journal of Food Science and Technology-mysore, 2010
    Co-Authors: J. E. Nagamani, K. S. Shivashankara, T. K. Roy
    Abstract:

    Spongy Tissue formation in ‘Alphonso’ mangoes (Mangifera indica L) is a major national problem leading to loss for farmers and traders. Spongy Tissue is whitish sponge like Tissue formed near the seed with insipid taste and off odour. Lipid peroxidation of membranes as studied by malondialdehyde formation was significantly higher in Spongy Tissue. Activities of antioxidative enzymes like superoxide dismutase, catalase, peroxidase and polyphenol oxidase were lower in Spongy Tissue. Among the antioxidative enzymes, activities of catalase and peroxidases were severely reduced leading to membrane damage in Spongy Tissue. A significant reduction in 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase and accumulation of ACC was also observed in Spongy Tissue. However, ACC synthase activity in Spongy Tissue was more compared to healthy Tissue. Results indicate that the membrane peroxidation leading to lower activity of ACC oxidase might lead to the formation of Spongy Tissue in ‘Alphonso’ mango.

S. Shivashankar - One of the best experts on this subject based on the ideXlab platform.

  • Rapid burst of ethylene evolution by premature seed: A warning sign for the onset of Spongy Tissue disorder in Alphonso mango fruit?
    Journal of biosciences, 2019
    Co-Authors: S. Shivashankar, Manoharan Sumathi
    Abstract:

    Moisture stress induced in premature seeds due to the breakdown of funiculus in Alphonso mango led to the burst of ethylene evolution, which in turn caused a sudden increase of polyphenol oxidase activity in the pulp, resulting in the development of a black spot near the seed base. Reduced levels of very long chain fatty acids in 70% mature seeds with black spots were associated with a sudden increase of cytokinins followed by a rapid rise of starch-metabolizing enzymes culminating in the onset of pre-germination events. Concurrently, an overproduction of p-OH benzoic acid inhibited amylase and polygalacturonase enzymes and led to partial degradation of the stored starch and pectin in the pulp. A parallel drop in climacteric ethylene production by the pulp led to incomplete ripening coupled with changes in composition, texture and aroma of the pulp, characteristic of Spongy Tissue. The results have provided strong experimental evidence to support the fact that increased competition for resources among developing fruits for the synthesis of seed fat plays a critical role in Spongy Tissue formation in Alphonso mango. The major highlight of the study is that rapid ethylene evolution by premature seed is an early warning sign for the initiation of Spongy Tissue formation in Alphonso mango.

  • Do seed VLCFAs trigger Spongy Tissue formation in Alphonso mango by inducing germination
    Journal of biosciences, 2015
    Co-Authors: S. Shivashankar, Manoharan Sumathi, T. K. Roy
    Abstract:

    Spongy Tissue is a physiological disorder in Alphonso mango caused by the inception of germination-associated events during fruit maturation on the tree, rendering the fruit inedible. Inter-fruit competition during active fruit growth is a major contributing factor for the disorder which leads to reduced fat content in Spongy Tissue affected fruits. This study was, therefore, carried out to determine the possible association between seed fats and ST formation. The study of the fat content during fruit growth showed that it increased gradually from 40% fruit maturity. At 70% maturity, however, there was a sudden increase of fat content of whole fruit, leading to acute competition and resulting in differential allocation of resources among developing fruits. As a result, the seed in Spongy-Tissue-affected mature ripe fruit showed a marked drop in the levels of fats and the two very long chain fatty acids (VLCFAs), tetracosanoic acid and hexacosanoic acid together with an increase of linolenic acid and a fall in oleic acid contents, which are known to be key determinants for the initiation of pre-germination events in seed. Subsequently, a rise in the level of cytokinin and gibberellins in ST seed associated with a fall in abscisic acid level clearly signalled the onset of germination. Concurrently, a significant reduction in the ratio of linolenic acid/linoleic acid in pulp led to the loss of membrane integrity, cell death and the eventual formation of Spongy Tissue. Based on the above, it is concluded that a significant reduction in the biosynthesis of VLCFAs in seeds during fruit growth might trigger pre-germination events followed by a cascade of biochemical changes in the pulp, leading to lipid peroxidation and membrane injury in pulp culminating in ST development. Thus, this study presents crucial experimental evidence to highlight the critical role played by VLCFAs in inducing ST formation in Alphonso mango during the pre-harvest phase of fruit growth.

  • a protocol for the control of Spongy Tissue disorder in alphonso mango by pre harvest treatments
    2014
    Co-Authors: S. Shivashankar, M Sumathi, Shivashankar S Indian
    Abstract:

    Spongy Tissue (ST) of Alphonso mango is the most important physiological disorder which causes grave loss of fruit quality in ripe fruits without showing external symptoms. Until recently, there was no remedy to overcome the malady, as there were speculations regarding the nature of its origin. However, following the crucial findings that the disorder arises due to the premature onset of germinationassociated events in the seed of the developing fruit, field experiments were initiated to develop a protocol to treat the disorder. Results clearly showed that application of salt solutions as a pre-harvest spray between 60 and 70% fruit maturity gave significant reduction in the incidence of the malady. Among the treatments, application of nutrient mix containing a mixture of macro and micronutrients and sea water produced fruits with an ST incidence level of <5%. Analysis of data revealed that the osmotic effect generated by hypertonic salt solutions was primarily responsible for withholding the movement of water from mesocarp to seed thus preventing the onset of germination-associated events and consequently a reduced incidence of Spongy Tissue. Pre-harvest application of the nutrient mix containing macro and micronutrients or sea water on developing fruits between 60 and 70% maturity stage effectively reduced the incidence of ST to <5% compared to 54.3% in control, besides improving the shelf life and fruit quality. The study also demonstrated that treatment of fruits before reaching 60% maturity or after crossing 70% maturity was not as effective in reducing ST incidence. The method offers an easy, effective, economical and eco-friendly solution to overcome the dreaded disorder at the field level thus allowing farmers to produce superior quality Alphonso fruits free from the malady.

  • Biochemical changes in seed and mesocarp of mango (Mangifera indica L.) cv. ‘Alphonso’ and their significance during the development of Spongy Tissue
    The Journal of Horticultural Science and Biotechnology, 2007
    Co-Authors: S. Shivashankar, V. Ravindra, H. C. Louis
    Abstract:

    SummaryBiochemical studies were conducted on both seed and mesocarp Tissue of ‘Alphonso’ mango during fruit development and the fruit ripening stages to examine the possible role of seed in inducing the formation of Spongy Tissue. Fruits were analysed for selected key enzymes of carbohydrate, fat and respiratory metabolism, and related biochemical constituents. Invariably, the incidence of Spongy Tissue was associated with an increase in amylase and lipase activities in the seed, and a concomitant reduction in mesocarp Tissue. Exogenously applied gibberellic acid (GA3) induced the formation of Spongy Tissue with enhanced amylase activity, while paclobutrazol (PBZ) reduced the incidence of Spongy Tissue, with a reduction in amylase activity in the seed. The results clearly indicated that the shift of seed into germination mode provided a trigger for the formation of Spongy Tissue in the mesocarp.

  • biochemical changes in seed and mesocarp of mango mangifera indica l cv alphonso and their significance during the development of Spongy Tissue
    Journal of Horticultural Science & Biotechnology, 2007
    Co-Authors: S. Shivashankar, V. Ravindra, H. C. Louis
    Abstract:

    SummaryBiochemical studies were conducted on both seed and mesocarp Tissue of ‘Alphonso’ mango during fruit development and the fruit ripening stages to examine the possible role of seed in inducing the formation of Spongy Tissue. Fruits were analysed for selected key enzymes of carbohydrate, fat and respiratory metabolism, and related biochemical constituents. Invariably, the incidence of Spongy Tissue was associated with an increase in amylase and lipase activities in the seed, and a concomitant reduction in mesocarp Tissue. Exogenously applied gibberellic acid (GA3) induced the formation of Spongy Tissue with enhanced amylase activity, while paclobutrazol (PBZ) reduced the incidence of Spongy Tissue, with a reduction in amylase activity in the seed. The results clearly indicated that the shift of seed into germination mode provided a trigger for the formation of Spongy Tissue in the mesocarp.

K. S. Shivashankara - One of the best experts on this subject based on the ideXlab platform.

  • Role of oxidative stress and the activity of ethylene biosynthetic enzymes on the formation of Spongy Tissue in ‘Alphonso’ mango
    Journal of food science and technology, 2010
    Co-Authors: J. E. Nagamani, K. S. Shivashankara, T. K. Roy
    Abstract:

    Spongy Tissue formation in ‘Alphonso’ mangoes (Mangifera indica L) is a major national problem leading to loss for farmers and traders. Spongy Tissue is whitish sponge like Tissue formed near the seed with insipid taste and off odour. Lipid peroxidation of membranes as studied by malondialdehyde formation was significantly higher in Spongy Tissue. Activities of antioxidative enzymes like superoxide dismutase, catalase, peroxidase and polyphenol oxidase were lower in Spongy Tissue. Among the antioxidative enzymes, activities of catalase and peroxidases were severely reduced leading to membrane damage in Spongy Tissue. A significant reduction in 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase and accumulation of ACC was also observed in Spongy Tissue. However, ACC synthase activity in Spongy Tissue was more compared to healthy Tissue. Results indicate that the membrane peroxidation leading to lower activity of ACC oxidase might lead to the formation of Spongy Tissue in ‘Alphonso’ mango.

  • role of oxidative stress and the activity of ethylene biosynthetic enzymes on the formation of Spongy Tissue in alphonso mango
    Journal of Food Science and Technology-mysore, 2010
    Co-Authors: J. E. Nagamani, K. S. Shivashankara, T. K. Roy
    Abstract:

    Spongy Tissue formation in ‘Alphonso’ mangoes (Mangifera indica L) is a major national problem leading to loss for farmers and traders. Spongy Tissue is whitish sponge like Tissue formed near the seed with insipid taste and off odour. Lipid peroxidation of membranes as studied by malondialdehyde formation was significantly higher in Spongy Tissue. Activities of antioxidative enzymes like superoxide dismutase, catalase, peroxidase and polyphenol oxidase were lower in Spongy Tissue. Among the antioxidative enzymes, activities of catalase and peroxidases were severely reduced leading to membrane damage in Spongy Tissue. A significant reduction in 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase and accumulation of ACC was also observed in Spongy Tissue. However, ACC synthase activity in Spongy Tissue was more compared to healthy Tissue. Results indicate that the membrane peroxidation leading to lower activity of ACC oxidase might lead to the formation of Spongy Tissue in ‘Alphonso’ mango.

  • Influence of Temperature on Spongy Tissue Formation in ‘Alphonso’ Mango
    International Journal of Fruit Science, 2008
    Co-Authors: Hemanth K. N. Vasanthaiah, Kundapura V. Ravishankar, P. Narayanaswamy, K. S. Shivashankara
    Abstract:

    ABSTRACT High temperatures induce physiological changes within the mango fruit. A study was conducted to determine the influence of the rate of transpiration and respiration on Spongy Tissue formation in ‘Alphonso’ mango. Spongy Tissue is a physiological disorder in ‘Alphonso’ mango. Both artificially and naturally induced Spongy Tissue showed low rates of transpiration and high rates of respiration as evidenced by stable oxygen isotope analysis and portable photosynthetic system readings. This condition builds up high temperatures within the fruits, leading to Tissue breakdown. The results of this study indicated that the rate of transpiration and respiration has an influence on fruit temperature, which in turn has an influence on normal fruit ripening processes.

  • Cloning and characterization of differentially expressed genes of internal breakdown in mango fruit (Mangifera indica).
    Journal of plant physiology, 2005
    Co-Authors: Hemanth K. N. Vasanthaiah, Kundapura V. Ravishankar, K. S. Shivashankara, Lalitha Anand, Pappana Narayanaswamy, Gullarachikkanahalli Mukunda, T. G. Prasad
    Abstract:

    Internal breakdown in mango fruits has become a major concern in recent years. This disorder renders the fruits unfit for human consumption. The overall loss due to this disorder is about 35-55%. Environmental and physiological factors like high temperature, humidity, respiration and low transpiration rates have been attributed to cause Spongy Tissue due to reduced loss of heat from fruits. Biochemical studies have shown that there is a reduction in pH, total soluble solids, ascorbic acid, total sugars and carotenoids, low reducing and non-reducing sugar contents, lower amylase and invertase activities and high acid and starch content in Spongy Tissue affected pulp. There are no reports on molecular studies to determine changes in gene expression in these Tissues. The present study was conducted using PCR based subtractive hybridization and RNA gel blot analysis of a few selected genes. The latter showed a higher expression of catalase, ubiquitin, alcohol dehydrogenase, coproporphyrinogen oxidase and keratin associated protein. A lower expression of ribosomal gene, fructose bisphosphate aldolase and cysthathionine gamma synthase was also noticed in Spongy Tissue. Biochemical studies indicated a lower amylase activity and a lower content of the total and reducing sugars in Spongy Tissue as compared to healthy Tissue. Analyses of results indicate that oxidative stress may be one of the causes for formation of Spongy Tissue, which affects the expression of many genes. The role of these genes in Spongy Tissue formation is discussed.

  • Relationship of leaf and fruit transpiration rates to the incidence of Spongy Tissue disorder in two mango (Mangifera indica L.) cultivars
    Scientia Horticulturae, 1999
    Co-Authors: K. S. Shivashankara, C.k Mathai
    Abstract:

    The relationship of leaf and fruit transpiration rates with the incidence of Spongy Tissue in mango cultivars Dashahari (free from Spongy Tissue) and Alphonso (susceptible to Spongy Tissue) was investigated. Leaf transpiration rates were similar in both the cultivars, however the fruit transpiration rates were significantly higher in cv. Dashahari. Artificially induced variations in fruit transpiration rates using perforated polythene covers and vaseline coating of fruits also resulted in significant changes in the incidence of Spongy Tissue in cv. Alphonso. The significant and negative relationship observed between the fruit transpiration rate and the Spongy Tissue suggests that the lower fruit transpiration rates in cv. Alphonso are a varietal specific trait, which results in slower movement of water and minerals to the fruits from soil leading to the development of Spongy Tissue.

Manoharan Sumathi - One of the best experts on this subject based on the ideXlab platform.

  • Rapid burst of ethylene evolution by premature seed: A warning sign for the onset of Spongy Tissue disorder in Alphonso mango fruit?
    Journal of biosciences, 2019
    Co-Authors: S. Shivashankar, Manoharan Sumathi
    Abstract:

    Moisture stress induced in premature seeds due to the breakdown of funiculus in Alphonso mango led to the burst of ethylene evolution, which in turn caused a sudden increase of polyphenol oxidase activity in the pulp, resulting in the development of a black spot near the seed base. Reduced levels of very long chain fatty acids in 70% mature seeds with black spots were associated with a sudden increase of cytokinins followed by a rapid rise of starch-metabolizing enzymes culminating in the onset of pre-germination events. Concurrently, an overproduction of p-OH benzoic acid inhibited amylase and polygalacturonase enzymes and led to partial degradation of the stored starch and pectin in the pulp. A parallel drop in climacteric ethylene production by the pulp led to incomplete ripening coupled with changes in composition, texture and aroma of the pulp, characteristic of Spongy Tissue. The results have provided strong experimental evidence to support the fact that increased competition for resources among developing fruits for the synthesis of seed fat plays a critical role in Spongy Tissue formation in Alphonso mango. The major highlight of the study is that rapid ethylene evolution by premature seed is an early warning sign for the initiation of Spongy Tissue formation in Alphonso mango.

  • Do seed VLCFAs trigger Spongy Tissue formation in Alphonso mango by inducing germination
    Journal of biosciences, 2015
    Co-Authors: S. Shivashankar, Manoharan Sumathi, T. K. Roy
    Abstract:

    Spongy Tissue is a physiological disorder in Alphonso mango caused by the inception of germination-associated events during fruit maturation on the tree, rendering the fruit inedible. Inter-fruit competition during active fruit growth is a major contributing factor for the disorder which leads to reduced fat content in Spongy Tissue affected fruits. This study was, therefore, carried out to determine the possible association between seed fats and ST formation. The study of the fat content during fruit growth showed that it increased gradually from 40% fruit maturity. At 70% maturity, however, there was a sudden increase of fat content of whole fruit, leading to acute competition and resulting in differential allocation of resources among developing fruits. As a result, the seed in Spongy-Tissue-affected mature ripe fruit showed a marked drop in the levels of fats and the two very long chain fatty acids (VLCFAs), tetracosanoic acid and hexacosanoic acid together with an increase of linolenic acid and a fall in oleic acid contents, which are known to be key determinants for the initiation of pre-germination events in seed. Subsequently, a rise in the level of cytokinin and gibberellins in ST seed associated with a fall in abscisic acid level clearly signalled the onset of germination. Concurrently, a significant reduction in the ratio of linolenic acid/linoleic acid in pulp led to the loss of membrane integrity, cell death and the eventual formation of Spongy Tissue. Based on the above, it is concluded that a significant reduction in the biosynthesis of VLCFAs in seeds during fruit growth might trigger pre-germination events followed by a cascade of biochemical changes in the pulp, leading to lipid peroxidation and membrane injury in pulp culminating in ST development. Thus, this study presents crucial experimental evidence to highlight the critical role played by VLCFAs in inducing ST formation in Alphonso mango during the pre-harvest phase of fruit growth.

Jihua Hou - One of the best experts on this subject based on the ideXlab platform.

  • variation in leaf anatomical traits from tropical to cold temperate forests and linkage to ecosystem functions
    Functional Ecology, 2018
    Co-Authors: Congcong Liu, Miao Tian, Hao Yang, Dali Guo, Melinda D. Smith, Jihua Hou
    Abstract:

    Leaf anatomical traits may reflect plants adaption to environmental changes and influence ecosystem functions, as they regulate light absorption and gas exchange to some extent. Here, we hypothesized that leaf anatomical traits were closely related to gross primary productivity (GPP) because photosynthesis commonly occurs in the chloroplasts of palisade and Spongy Tissues in leaf. Eight leaf anatomical traits were measured in 916 plant species inhabiting from tropical to cold-temperate forests in eastern China: adaxial epidermis thickness (AD), abaxial epidermis thickness (AB), leaf thickness (LT), palisade Tissue thickness (PT), and Spongy Tissue thickness (ST), palisade–Spongy Tissue ratio (PT/ST), palisade Tissue–leaf thickness ratio (PT/LT), and Spongy Tissue–leaf thickness ratio (ST/LT). Leaf anatomical traits showed significant latitudinal patterns at species, plant functional group (PFG), and community levels (p < .05), and they differed between PFG and community. Temperature and precipitation were the main factors influencing AD, AB, PT/ST, and PT/LT, explaining 33–72% of the total variation at large scale. Furthermore, AB, LT, PT/ST, and PT/LT were significantly correlated with the aridity index. Our findings filled the data gap of plant anatomical traits at regional scales, and broadened current knowledge on the adaptation strategies of plant anatomical traits, which also provided new evidence for linkages of plant traits and functioning across natural communities. A plain language summary is available for this article.

  • Variation in leaf anatomical traits from tropical to cold‐temperate forests and linkage to ecosystem functions
    Functional Ecology, 2017
    Co-Authors: Congcong Liu, Miao Tian, Hao Yang, Dali Guo, Melinda D. Smith, Jihua Hou
    Abstract:

    Leaf anatomical traits may reflect plants adaption to environmental changes and influence ecosystem functions, as they regulate light absorption and gas exchange to some extent. Here, we hypothesized that leaf anatomical traits were closely related to gross primary productivity (GPP) because photosynthesis commonly occurs in the chloroplasts of palisade and Spongy Tissues in leaf. Eight leaf anatomical traits were measured in 916 plant species inhabiting from tropical to cold-temperate forests in eastern China: adaxial epidermis thickness (AD), abaxial epidermis thickness (AB), leaf thickness (LT), palisade Tissue thickness (PT), and Spongy Tissue thickness (ST), palisade–Spongy Tissue ratio (PT/ST), palisade Tissue–leaf thickness ratio (PT/LT), and Spongy Tissue–leaf thickness ratio (ST/LT). Leaf anatomical traits showed significant latitudinal patterns at species, plant functional group (PFG), and community levels (p