The Experts below are selected from a list of 8115 Experts worldwide ranked by ideXlab platform
Klaus Mummenhoff - One of the best experts on this subject based on the ideXlab platform.
-
evidence that an evolutionary transition from dehiscent to indehiscent fruits in Lepidium brassicaceae was caused by a change in the control of valve margin identity genes
Plant Journal, 2013Co-Authors: Andreas Mühlhausen, Klaus Mummenhoff, Teresa Lenser, Gunter TheisenAbstract:Summary In the Brassicaceae, indehiscent fruits evolved from dehiscent fruits several times independently. Here we use closely related wild species of the genus Lepidium as a model system to analyse the underlying developmental genetic mechanisms in a candidate gene approach. ALCATRAZ (ALC), INDEHISCENT (IND), SHATTERPROOF1 (SHP1) and SHATTERPROOF2 (SHP2) are known fruit developmental genes of Arabidopsis thaliana that are expressed in the fruit valve margin governing dehiscence zone formation. Comparative expression analysis by quantitative RT-PCR, Northern blot and in situ hybridization show that their orthologues from Lepidium campestre (dehiscent fruits) are similarly expressed at valve margins. In sharp contrast, expression of the respective orthologues is abolished in the corresponding tissue of indehiscent Lepidium appelianum fruits, indicating that changes in the genetic pathway identified in A. thaliana caused the transition from dehiscent to indehiscent fruits in the investigated species. As parallel mutations in different genes are quite unlikely, we conclude that the changes in gene expression patterns are probably caused by changes in upstream regulators of ALC, IND and SHP1/2, possible candidates from A. thaliana being FRUITFULL (FUL), REPLUMLESS (RPL) and APETALA2 (AP2). However, neither expression analyses nor functional tests in transgenic plants provided any evidence that the FUL or RPL orthologues of Lepidium were involved in evolution of fruit indehiscence in Lepidium. In contrast, stronger expression of AP2 in indehiscent compared to dehiscent fruits identifies AP2 as a candidate gene that deserves further investigation.
-
STUBENDORFFIA AND WINKLERA BELONG TO THE EXPANDED Lepidium (BRASSICACEAE)
Edinburgh Journal of Botany, 2011Co-Authors: I. A. Al-shehbaz, Klaus MummenhoffAbstract:The genus Stubendorffia (Brassicaceae) is distinguished from Lepidium solely by the dehiscent vs. indehiscent angustiseptate fruits. By contrast, Winklera is separated from Lepidium by a combination of perennial habit, pinnatisect leaves, yellow flowers, and wingless fruits, characters all of which occur individually and in various combinations within Lepidium. Extensive molecular studies strongly show that Winklera and polyphyletic Stubendorffia are nested within the earlier-published Lepidium and, therefore, the three genera are herein formally united. The new name Lepidium pavlovii and 10 new combinations, L. afghanicum, L. apterum, L. botschantzevii, L. curvinervium, L. lipskyi, L. olgae, L. orientalis, L. patrinoides, L. pterocarpum, and L. silaifolium, are proposed. Lepidium apterum is lectotypified. A complete generic synonymy of Lepidium and an expanded generic description are presented.
-
Evolution of fruit dehiscence in Brassicaceae - examples from Aethionema and Lepidium.
Acta Horticulturae, 2010Co-Authors: Andreas Mühlhausen, Alexander Polster, G. Theissen, Klaus MummenhoffAbstract:Most species of the Brassicaceae develop fruits in which seeds are released through a process termed fruit dehiscence. To provide a phylogenetic perspective for fruit dehiscence, the Arabidopsis model system will be widened here by two other systems from Brassicaceae. Some genera in Brassicaceae develop indehiscent fruits that do not release ripe seeds. The genus Lepidium comprises closely related species with either dehiscent (e.g., Lepidium campestre) or indehiscent fruits (e.g. L. appelianum). Recent phylogenies based on molecular data suggest that indehiscent fruits evolved several times independently in different clades from dehiscent fruits. The genus Aethionema is the sister group to all other extant Brassicaceae. Some species of Aethionema are heterocarpic, meaning that they develop both dehiscent and indehiscent fruits within the same infructescensce. Thus, both Lepidium and Aethionema represent interesting model systems to investigate the evolution of fruit dehiscence. Molecular genetic studies on fruit dehiscence and indehiscence in the model system Arabidopsis have been used to define candidate genes which might play a role in forming indehiscent fruits in Lepidium and Aethionema. Understanding the mechanisms involved in the transformation of dehiscent into indehiscent fruits in the same infructescence (Aethionema) and in closely related species (Lepidium) could provide general insights into the evolution of morphological traits in the Brassicaceae and beyond.
-
A bicontinental origin of polyploid Australian/New Zealand Lepidium species (Brassicaceae)? Evidence from genomic in situ hybridization
Annals of botany, 2009Co-Authors: Tom Dierschke, Terezie Mandáková, Martin A. Lysak, Klaus MummenhoffAbstract:†Background and Aims Incongruence between chloroplast and nuclear DNA phylogenies, and single additive nucleotide positions in internal transcribed spacer (ITS) sequences of polyploid Australian/New Zealand (NZ) Lepidium species have been used to suggest a bicontinental hybrid origin. This pattern was explained by two trans-oceanic dispersals of Lepidium species from California and Africa and subsequent hybridization followed by homogenization of the ribosomal DNA sequence either to the Californian (C-clade) or to the African ITS-type (A-clade) in two different ITS-lineages of Australian/NZ Lepidium polyploids. †Methods Genomic in situ hybridization (GISH) was used to unravel the genomic origin of polyploid Australian/ NZ Lepidium species. Fluorescence in situ hybridization (FISH) with ribosomal DNA (rDNA) probes was applied to test the purported ITS evolution, and to facilitate chromosome counting in high-numbered polyploids. †Key Results In Australian/NZ A-clade Lepidium polyploids, GISH identified African and Australian/NZ C-clade species as putative ancestral genomes. Neither the African nor the Californian genome were detected in Australian/NZ C-clade species and the Californian genome was not detected in Australian/NZ A-clade species. Five of the eight polyploid species (from 7x to 11x) displayed a diploid-like set of rDNA loci. Even the undecaploid species Lepidium muelleriferdinandi (2n ¼ 11x ¼ 88) showed only one pair of each rDNA repeat. In A-clade allopolyploids, in situ rDNA localization combined with GISH corroborated the presence of the African ITS-type. †Conclusions The nuclear genomes of African and Australian/NZ C-clade species were detected by GISH in allopolyploid Australian/NZ Lepidium species of the A-clade, supporting their hybrid origin. The presumed hybrid origin of Australian/NZ C-clade taxa could not be confirmed. Hence, it is assumed that Californian ancestral taxa experienced rapid radiation in Australia/NZ into extant C-clade polyploid taxa followed by hybridization with African species. As a result, A-clade allopolyploid Lepidium species share the Californian chloroplast type and the African ITS-type with the C-clade Australian/NZ polyploid and African diploid species, respectively.
-
Should Cardaria draba (L.) Desv. be classified within the genus Lepidium L. (Brassicaceae)? Evidence from subunit polypeptide composition of RUBISCO
Feddes Repertorium, 2008Co-Authors: Klaus MummenhoffAbstract:The polypeptide composition of the large and small subunits of ribulose-1,5-bisphosphate carboxylase/oxy-genase (RUBISCO) from Cardaria draba (L.) DESV. (Brassicaceae) and from representatives of the related genus Lepidium L. have been studied by isoelectric focusing (IEF) analysis. In the literature Cardaria DESV. is either treated as a separate genus or as a section within the genus Lepidium Cardaria draba (L.) DESV. and three Lepidium taxa of section Lepia (DESV.) DC. are characterized by identical polypeptide patterns otherwise not found in Lepidium. RUBISCO data would preliminarily suggest that C. draba has its closest relatives within Lepidium section Lepia and therefore could possibly be placed best within this section. Mithilfe der isoelektrischen Fokussierungsmethode wurde die Polypeptidzusammensetzung der grosen und kleinen Untereinheiten des Enzyms Ribulose-1,5-Bisphosphat Carboxylase/Oxygenase (RUBISCO) von Cardaria draba (L.) DESV. (Brassicaceae) und Vertretern der verwandten Gattung Lepidium L. analysiert. In der Literatur wird Cardaria DESV. entweder als eigenstandige Gattung oder als eine Sektion innerhalb von Lepidium aufgefast. Cardaria draba und Vertreter der Sektion Lepia (DESV.) DC. aus der Gattung Lepidium sind durch identische Polypeptid muster der RUBISCO-Untereinheiten charakterisiert, die ansonsten nicht in der Gattung Lepidium auftreten. Diese Ergebnisse lassen vermuten, das sich die nachsten Verwandten von C. draba in der Sektion Lepia der Gattung Lepidium befinden und das somit C. draba in die Sektion Lepia zu stellen ist.
D. R. Given - One of the best experts on this subject based on the ideXlab platform.
-
The role of seabirds and seals in the survival of coastal plants: lessons from New Zealand Lepidium (Brassicaceae)
Biodiversity & Conservation, 1997Co-Authors: D. A. Norton, P. J. Delange, P. J. Garnock-jones, D. R. GivenAbstract:Six of the eight indigenous New Zealand Lepidium species are coastal, and have restricted or reduced distributions. One is extinct and the remainder are considered threatened with extinction. This limited distribution is in marked contrast to their apparent abundance in the eighteenth and early nineteenth centuries (1760s–1830s). Accounts from the voyages of Cook, Surville and d'Urville describe L. oleraceum as an abundant coastal plant which was collected extensively for use as an antiscorbutic. However, by the late 19th century, resident botanists were expressing concern about the marked decline in coastal species of Lepidium, a decline which has continued to the present. Ecologically, coastal species of Lepidium are similar, being restricted to open sites often close to the high tide mark. They are commonly associated with bird colonies, and occasionally with fur seal colonies. Traditionally their decline has been attributed to introduced herbivores. However, wild grazing animals were not common until the end of the 19th century, well after the initial decline had occurred. Other possible reasons for their decline include herbivory and predation by rats, and by fungal and invertebrate pests of cultivated Brassicaceae, overcollecting and coastal development. However, we suggest that a major factor in the decline of coastal Lepidium species was a decline in coastal seabirds through predation and seals through culling. Seabirds and seals are critical for the survival of Lepidium species by keeping sites open through disturbance, dispersing seed, and providing nutrient enrichment for plant growth, and their loss has resulted in decline of habitat for Lepidium.
-
The role of seabirds and seals in the survival of coastal plants: lessons from New Zealand Lepidium (Brassicaceae)
Biodiversity & Conservation, 1997Co-Authors: D. A. Norton, P. J. Delange, P. J. Garnock-jones, D. R. GivenAbstract:Six of the eight indigenous New Zealand Lepidium species are coastal, and have restricted or reduced distributions. One is extinct and the remainder are considered threatened with extinction. This limited distribution is in marked contrast to their apparent abundance in the eighteenth and early nineteenth centuries (1760s–1830s). Accounts from the voyages of Cook, Surville and d'Urville describe L. oleraceum as an abundant coastal plant which was collected extensively for use as an antiscorbutic. However, by the late 19th century, resident botanists were expressing concern about the marked decline in coastal species of Lepidium, a decline which has continued to the present. Ecologically, coastal species of Lepidium are similar, being restricted to open sites often close to the high tide mark. They are commonly associated with bird colonies, and occasionally with fur seal colonies. Traditionally their decline has been attributed to introduced herbivores. However, wild grazing animals were not common until the end of the 19th century, well after the initial decline had occurred. Other possible reasons for their decline include herbivory and predation by rats, and by fungal and invertebrate pests of cultivated Brassicaceae, overcollecting and coastal development. However, we suggest that a major factor in the decline of coastal Lepidium species was a decline in coastal seabirds through predation and seals through culling. Seabirds and seals are critical for the survival of Lepidium species by keeping sites open through disturbance, dispersing seed, and providing nutrient enrichment for plant growth, and their loss has resulted in decline of habitat for Lepidium.
D. A. Norton - One of the best experts on this subject based on the ideXlab platform.
-
The role of seabirds and seals in the survival of coastal plants: lessons from New Zealand Lepidium (Brassicaceae)
Biodiversity & Conservation, 1997Co-Authors: D. A. Norton, P. J. Delange, P. J. Garnock-jones, D. R. GivenAbstract:Six of the eight indigenous New Zealand Lepidium species are coastal, and have restricted or reduced distributions. One is extinct and the remainder are considered threatened with extinction. This limited distribution is in marked contrast to their apparent abundance in the eighteenth and early nineteenth centuries (1760s–1830s). Accounts from the voyages of Cook, Surville and d'Urville describe L. oleraceum as an abundant coastal plant which was collected extensively for use as an antiscorbutic. However, by the late 19th century, resident botanists were expressing concern about the marked decline in coastal species of Lepidium, a decline which has continued to the present. Ecologically, coastal species of Lepidium are similar, being restricted to open sites often close to the high tide mark. They are commonly associated with bird colonies, and occasionally with fur seal colonies. Traditionally their decline has been attributed to introduced herbivores. However, wild grazing animals were not common until the end of the 19th century, well after the initial decline had occurred. Other possible reasons for their decline include herbivory and predation by rats, and by fungal and invertebrate pests of cultivated Brassicaceae, overcollecting and coastal development. However, we suggest that a major factor in the decline of coastal Lepidium species was a decline in coastal seabirds through predation and seals through culling. Seabirds and seals are critical for the survival of Lepidium species by keeping sites open through disturbance, dispersing seed, and providing nutrient enrichment for plant growth, and their loss has resulted in decline of habitat for Lepidium.
-
The role of seabirds and seals in the survival of coastal plants: lessons from New Zealand Lepidium (Brassicaceae)
Biodiversity & Conservation, 1997Co-Authors: D. A. Norton, P. J. Delange, P. J. Garnock-jones, D. R. GivenAbstract:Six of the eight indigenous New Zealand Lepidium species are coastal, and have restricted or reduced distributions. One is extinct and the remainder are considered threatened with extinction. This limited distribution is in marked contrast to their apparent abundance in the eighteenth and early nineteenth centuries (1760s–1830s). Accounts from the voyages of Cook, Surville and d'Urville describe L. oleraceum as an abundant coastal plant which was collected extensively for use as an antiscorbutic. However, by the late 19th century, resident botanists were expressing concern about the marked decline in coastal species of Lepidium, a decline which has continued to the present. Ecologically, coastal species of Lepidium are similar, being restricted to open sites often close to the high tide mark. They are commonly associated with bird colonies, and occasionally with fur seal colonies. Traditionally their decline has been attributed to introduced herbivores. However, wild grazing animals were not common until the end of the 19th century, well after the initial decline had occurred. Other possible reasons for their decline include herbivory and predation by rats, and by fungal and invertebrate pests of cultivated Brassicaceae, overcollecting and coastal development. However, we suggest that a major factor in the decline of coastal Lepidium species was a decline in coastal seabirds through predation and seals through culling. Seabirds and seals are critical for the survival of Lepidium species by keeping sites open through disturbance, dispersing seed, and providing nutrient enrichment for plant growth, and their loss has resulted in decline of habitat for Lepidium.
P. J. Delange - One of the best experts on this subject based on the ideXlab platform.
-
The role of seabirds and seals in the survival of coastal plants: lessons from New Zealand Lepidium (Brassicaceae)
Biodiversity & Conservation, 1997Co-Authors: D. A. Norton, P. J. Delange, P. J. Garnock-jones, D. R. GivenAbstract:Six of the eight indigenous New Zealand Lepidium species are coastal, and have restricted or reduced distributions. One is extinct and the remainder are considered threatened with extinction. This limited distribution is in marked contrast to their apparent abundance in the eighteenth and early nineteenth centuries (1760s–1830s). Accounts from the voyages of Cook, Surville and d'Urville describe L. oleraceum as an abundant coastal plant which was collected extensively for use as an antiscorbutic. However, by the late 19th century, resident botanists were expressing concern about the marked decline in coastal species of Lepidium, a decline which has continued to the present. Ecologically, coastal species of Lepidium are similar, being restricted to open sites often close to the high tide mark. They are commonly associated with bird colonies, and occasionally with fur seal colonies. Traditionally their decline has been attributed to introduced herbivores. However, wild grazing animals were not common until the end of the 19th century, well after the initial decline had occurred. Other possible reasons for their decline include herbivory and predation by rats, and by fungal and invertebrate pests of cultivated Brassicaceae, overcollecting and coastal development. However, we suggest that a major factor in the decline of coastal Lepidium species was a decline in coastal seabirds through predation and seals through culling. Seabirds and seals are critical for the survival of Lepidium species by keeping sites open through disturbance, dispersing seed, and providing nutrient enrichment for plant growth, and their loss has resulted in decline of habitat for Lepidium.
-
The role of seabirds and seals in the survival of coastal plants: lessons from New Zealand Lepidium (Brassicaceae)
Biodiversity & Conservation, 1997Co-Authors: D. A. Norton, P. J. Delange, P. J. Garnock-jones, D. R. GivenAbstract:Six of the eight indigenous New Zealand Lepidium species are coastal, and have restricted or reduced distributions. One is extinct and the remainder are considered threatened with extinction. This limited distribution is in marked contrast to their apparent abundance in the eighteenth and early nineteenth centuries (1760s–1830s). Accounts from the voyages of Cook, Surville and d'Urville describe L. oleraceum as an abundant coastal plant which was collected extensively for use as an antiscorbutic. However, by the late 19th century, resident botanists were expressing concern about the marked decline in coastal species of Lepidium, a decline which has continued to the present. Ecologically, coastal species of Lepidium are similar, being restricted to open sites often close to the high tide mark. They are commonly associated with bird colonies, and occasionally with fur seal colonies. Traditionally their decline has been attributed to introduced herbivores. However, wild grazing animals were not common until the end of the 19th century, well after the initial decline had occurred. Other possible reasons for their decline include herbivory and predation by rats, and by fungal and invertebrate pests of cultivated Brassicaceae, overcollecting and coastal development. However, we suggest that a major factor in the decline of coastal Lepidium species was a decline in coastal seabirds through predation and seals through culling. Seabirds and seals are critical for the survival of Lepidium species by keeping sites open through disturbance, dispersing seed, and providing nutrient enrichment for plant growth, and their loss has resulted in decline of habitat for Lepidium.
P. J. Garnock-jones - One of the best experts on this subject based on the ideXlab platform.
-
The role of seabirds and seals in the survival of coastal plants: lessons from New Zealand Lepidium (Brassicaceae)
Biodiversity & Conservation, 1997Co-Authors: D. A. Norton, P. J. Delange, P. J. Garnock-jones, D. R. GivenAbstract:Six of the eight indigenous New Zealand Lepidium species are coastal, and have restricted or reduced distributions. One is extinct and the remainder are considered threatened with extinction. This limited distribution is in marked contrast to their apparent abundance in the eighteenth and early nineteenth centuries (1760s–1830s). Accounts from the voyages of Cook, Surville and d'Urville describe L. oleraceum as an abundant coastal plant which was collected extensively for use as an antiscorbutic. However, by the late 19th century, resident botanists were expressing concern about the marked decline in coastal species of Lepidium, a decline which has continued to the present. Ecologically, coastal species of Lepidium are similar, being restricted to open sites often close to the high tide mark. They are commonly associated with bird colonies, and occasionally with fur seal colonies. Traditionally their decline has been attributed to introduced herbivores. However, wild grazing animals were not common until the end of the 19th century, well after the initial decline had occurred. Other possible reasons for their decline include herbivory and predation by rats, and by fungal and invertebrate pests of cultivated Brassicaceae, overcollecting and coastal development. However, we suggest that a major factor in the decline of coastal Lepidium species was a decline in coastal seabirds through predation and seals through culling. Seabirds and seals are critical for the survival of Lepidium species by keeping sites open through disturbance, dispersing seed, and providing nutrient enrichment for plant growth, and their loss has resulted in decline of habitat for Lepidium.
-
The role of seabirds and seals in the survival of coastal plants: lessons from New Zealand Lepidium (Brassicaceae)
Biodiversity & Conservation, 1997Co-Authors: D. A. Norton, P. J. Delange, P. J. Garnock-jones, D. R. GivenAbstract:Six of the eight indigenous New Zealand Lepidium species are coastal, and have restricted or reduced distributions. One is extinct and the remainder are considered threatened with extinction. This limited distribution is in marked contrast to their apparent abundance in the eighteenth and early nineteenth centuries (1760s–1830s). Accounts from the voyages of Cook, Surville and d'Urville describe L. oleraceum as an abundant coastal plant which was collected extensively for use as an antiscorbutic. However, by the late 19th century, resident botanists were expressing concern about the marked decline in coastal species of Lepidium, a decline which has continued to the present. Ecologically, coastal species of Lepidium are similar, being restricted to open sites often close to the high tide mark. They are commonly associated with bird colonies, and occasionally with fur seal colonies. Traditionally their decline has been attributed to introduced herbivores. However, wild grazing animals were not common until the end of the 19th century, well after the initial decline had occurred. Other possible reasons for their decline include herbivory and predation by rats, and by fungal and invertebrate pests of cultivated Brassicaceae, overcollecting and coastal development. However, we suggest that a major factor in the decline of coastal Lepidium species was a decline in coastal seabirds through predation and seals through culling. Seabirds and seals are critical for the survival of Lepidium species by keeping sites open through disturbance, dispersing seed, and providing nutrient enrichment for plant growth, and their loss has resulted in decline of habitat for Lepidium.