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Sushil Kumar - One of the best experts on this subject based on the ideXlab platform.
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Parallelismic homoplasy of leaf and Stipule phenotypes among genetic variants of Pisum sativum and Medicago truncatula and some taxa of Papilionoideae, Caesalpinioideae and Mimosoideae subfamilies of the Leguminosae flora of Delhi
Plant Systematics and Evolution, 2013Co-Authors: Vishakha Sharma, Sushil KumarAbstract:The leguminous flora of Delhi comprises 78 Papilionoideae, 24 Caesalpinioideae and 24 Mimosoideae species; 80 of them are perennials. Five types of imparipinnate and two types of paripinnate compound leaves were observed in the species. The paripinnate leaves are bipinnate in 25 species (mostly mimosoid) and bifoliate in two species. The imparipinnate leaves were trifoliate or multifoliate in 59 papilionoid species and multifoliate in 16 caesalpinioid species; four of the papilionoid species produced leafletted and tendrilled unipinnate leaves. Leaves were bifacially simple in 22 species, simple with ectopic terminal growth in one species and simple tendril in one species. Twenty-one species (mostly mimosoid) were devoid of Stipules. In 82 species Stipules were small and free. Stipules were large and lobed in 17 species and large and adnate in four species. Two species of Caesalpinioideae produce compound leaf-like Stipules. All four Stipule phenotypes of 126 species corresponded with stipular phenotypes observed in wild type, coch , st and coch st genotypes of the model legume P. sativum . The seven leaf phenotypes observed in 126 species corresponded with phenotypes expected among combinations of uni ( uni - tac ), af , ins , mfp and tl mutants of P. sativum and sgl1 , cfl1 , slm1 and palm1 mutants of M. truncatula , also an IRL model legume. All the variation in leaf and Stipule morphologies observed in the leguminous flora of Delhi could be explained in terms of the gene regulatory networks already revealed in P. sativum and M. truncatula . It is hypothesized that the ancestral gene regulatory networks for leaves and Stipules produced in Leguminosae were like that prevalent in P. sativum .
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Auxin transport inhibitor induced low complexity petiolated leaves and sessile leaf-like Stipules and architectures of heritable leaf and Stipule mutants in Pisum sativum suggest that its simple lobed Stipules and compound leaf represent ancestral fo
Journal of Genetics, 2013Co-Authors: Arvind Kumar Kumar, Mali Ram Hindala, Vishakha Sharma, Moinuddin Khan, Sushil KumarAbstract:In angiosperms, leaf and Stipule architectures are inherited species-specific traits. Variation in leaf and Stipule sizes, and forms result from the interaction between abiotic and biotic stimuli, and gene regulatory network(s) that underlie the leaf and Stipule developmental programme(s). Here, correspondence between variation in leaf and Stipule architectures described for extant angiosperms and that induced mutationally and by imposition of stress in model angiosperm species, especially in Pisum sativum, was detected. Following inferences were drawn from the observations. (i) Several leaf forms in P. sativum have origin in fusion of Stipule and leaf primordia. Perfoliate (and amplexicaul and connate) simple sessile leaves and sessile adnate leaves are the result of such primordial fusions. Reversal of changes in the gene regulatory network responsible for fusion products are thought to restore original Stipule and leaf conditions. (ii) Compound leaf formation in several different model plants, is a result of promotion of pathways for such condition by gene regulatory networks directed by KNOX1 and LEAFY transcription factors or intercalation of the gene networks directed by them. (iii) Gene regulatory network for compound leaves in P. sativum when mutated generates highly complex compound leaves on one hand and simple leaves on other hand. These altered conditions are mutationally reversible. (vi) Simple leaves in model plants such as Arabidopsis thaliana despite overexpression of KNOX1 orthologues do not become compound. (v) All forms of leaves, including simple leaf, probably have origins in a gene regulatory network of the kind present in P. sativum.
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Interaction between cochleata and Stipule-reduced mutations results in exstipulate hypertrophied leaves in Pisum sativum L.
Indian journal of experimental biology, 2013Co-Authors: Arvind Kumar, Vishakha Sharma, Sushil KumarAbstract:In the wild type P. sativum, each of the adult plant stem nodes, bears a pair of sessile foliaceous Stipules and a petiolated unipinnately compound leaf of 4 to 6 leaflets and 7-9 tendrils. The Stipule-reduced (st) and cochleata (coch) single null mutants and coch st double null mutant differ fom the wild type in respectively having sessile Stipules of much reduced size, petiolated simple and/or compound leaf-like Stipules and no Stipules. It is also known that coch leaves are somewhat bigger than st and wild type leaves. Here, pleiotropic phenotype of coch st double mutant was investigated. The morphologies of Stipules and leaf were quantified in the field grown plants and microcultured shoots, latter in the presence and absence of gibberellic acid and N-1-naphthylphthalamic acid. The observations showed that as compared to the corresponding plants or shoots of COCH ST (WT) genotype, (a) coch st plants bore leaves in which all the organs were hypertrophied; (b) full complement of leaflets and 3-5 tendrils were formed on leaf; (c) the microcultured coch st shoots were taller despite lower number of nodes, and (d) they also produced leaves in which all the organs were bigger and the ratio of leaflets/tendrils was higher. It was concluded that in coch st double mutant (a) ST function is essential for Stipule primordium differentiation, in the absence of COCH function and (b) absence of negative feedback loops between simple Stipules and compound leaf for metabolite utilization allows hypertrophied growth in leaves.
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Genetic interaction and mapping studies on the leaflet development (lld) mutant in Pisum sativum
Journal of Genetics, 2012Co-Authors: Sushil Kumar, Vishakha Sharma, Swati Chaudhary, Arvind Kumar, Raghvendra Kumar Mishra, Renu KumariAbstract:In Pisum sativum , the completely penetrant leaflet development ( lld ) mutation is known to sporadically abort pinnae suborgans in the unipinnate compound leaf. Here, the frequency and morphology of abortion was studied in each of the leaf suborgans in 36 genotypes and in presence of auxin and gibberellin, and their antagonists. Various lld genotypes were constructed by multifariously recombining lld with a coch homeotic Stipule mutation and with af , ins , mare , mfp , tl and uni-tac leaf morphology mutations. It was observed that the suborgans at all levels of pinna subdivisions underwent lld -led abortion events at different stages of development. As in leafblades, lld aborted the pinnae in leaf-like compound coch Stipules. The lld mutation interacted with mfp synergistically and with other leaf mutations additively. The rod-shaped and trumpet-shaped aborted pea leaf suborgans mimicked the phenotype of aborted leaves in HD-ZIP-III-deficient Arabidopsis thaliana mutants. Suborganwise aborted morphologies in lld gnotypes were in agreement with basipetal differentiation of leaflets and acropetal differentiation in tendrils. Altogether, the observations suggested that LLD was the master regulator of pinna development. On the basis of molecular markers found linked to lld , its locus was positioned on the linkage group III of the P. sativum genetic map.
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Roles of Stipules Include Determination of Flowering Time and Pod Harvest Index in Garden Pea Grain Legume Pisum sativum
National Academy Science Letters, 2012Co-Authors: Vishakha Sharma, Sushil KumarAbstract:Stipules are known to photosynthesize and provide protection to the organs differentiating at the apex, associated leaf and branch-bud and inflorescence in the axil of leaf. Stipules are expected to affect the bearer plant in multiple ways. To reveal the relative roles of Stipules and leaves in Pisum sativum, the growth and development properties of leaf+ Stipule− (L+S−), leaf− Stipule+ (L−S+) and leaf+ Stipule+ (L+S+) plants were compared. The L−S+ and L+S− plants were respectively obtained by surgically removing the leaves and Stipules as soon as formed from the post-embryonic nodes of the genetically wild type Stipule and leaf bearing plants. The three sets of plants were arranged in a completely randomized design and sampled at the near harvest time for the phenotypic quantitation of ten primary and six secondary traits. The L−S+ and L+S− plants were later in flowering, scarce in branching and total number of nodes, lower in biomass and bore pods in lesser numbers than L+S+ plants. The biomass allocation to leaves and/or stems was higher in L+S−and L−S+ plants as compared to L+S+ plants in which pods were the principal organs of biomass deposition. The observations allowed the conclusions that both Stipules and leaves determine the flowering time and presence of Stipules maximizes biomass allocation to pods and in turn the harvest index.
Vishakha Sharma - One of the best experts on this subject based on the ideXlab platform.
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Parallelismic homoplasy of leaf and Stipule phenotypes among genetic variants of Pisum sativum and Medicago truncatula and some taxa of Papilionoideae, Caesalpinioideae and Mimosoideae subfamilies of the Leguminosae flora of Delhi
Plant Systematics and Evolution, 2013Co-Authors: Vishakha Sharma, Sushil KumarAbstract:The leguminous flora of Delhi comprises 78 Papilionoideae, 24 Caesalpinioideae and 24 Mimosoideae species; 80 of them are perennials. Five types of imparipinnate and two types of paripinnate compound leaves were observed in the species. The paripinnate leaves are bipinnate in 25 species (mostly mimosoid) and bifoliate in two species. The imparipinnate leaves were trifoliate or multifoliate in 59 papilionoid species and multifoliate in 16 caesalpinioid species; four of the papilionoid species produced leafletted and tendrilled unipinnate leaves. Leaves were bifacially simple in 22 species, simple with ectopic terminal growth in one species and simple tendril in one species. Twenty-one species (mostly mimosoid) were devoid of Stipules. In 82 species Stipules were small and free. Stipules were large and lobed in 17 species and large and adnate in four species. Two species of Caesalpinioideae produce compound leaf-like Stipules. All four Stipule phenotypes of 126 species corresponded with stipular phenotypes observed in wild type, coch , st and coch st genotypes of the model legume P. sativum . The seven leaf phenotypes observed in 126 species corresponded with phenotypes expected among combinations of uni ( uni - tac ), af , ins , mfp and tl mutants of P. sativum and sgl1 , cfl1 , slm1 and palm1 mutants of M. truncatula , also an IRL model legume. All the variation in leaf and Stipule morphologies observed in the leguminous flora of Delhi could be explained in terms of the gene regulatory networks already revealed in P. sativum and M. truncatula . It is hypothesized that the ancestral gene regulatory networks for leaves and Stipules produced in Leguminosae were like that prevalent in P. sativum .
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Auxin transport inhibitor induced low complexity petiolated leaves and sessile leaf-like Stipules and architectures of heritable leaf and Stipule mutants in Pisum sativum suggest that its simple lobed Stipules and compound leaf represent ancestral fo
Journal of Genetics, 2013Co-Authors: Arvind Kumar Kumar, Mali Ram Hindala, Vishakha Sharma, Moinuddin Khan, Sushil KumarAbstract:In angiosperms, leaf and Stipule architectures are inherited species-specific traits. Variation in leaf and Stipule sizes, and forms result from the interaction between abiotic and biotic stimuli, and gene regulatory network(s) that underlie the leaf and Stipule developmental programme(s). Here, correspondence between variation in leaf and Stipule architectures described for extant angiosperms and that induced mutationally and by imposition of stress in model angiosperm species, especially in Pisum sativum, was detected. Following inferences were drawn from the observations. (i) Several leaf forms in P. sativum have origin in fusion of Stipule and leaf primordia. Perfoliate (and amplexicaul and connate) simple sessile leaves and sessile adnate leaves are the result of such primordial fusions. Reversal of changes in the gene regulatory network responsible for fusion products are thought to restore original Stipule and leaf conditions. (ii) Compound leaf formation in several different model plants, is a result of promotion of pathways for such condition by gene regulatory networks directed by KNOX1 and LEAFY transcription factors or intercalation of the gene networks directed by them. (iii) Gene regulatory network for compound leaves in P. sativum when mutated generates highly complex compound leaves on one hand and simple leaves on other hand. These altered conditions are mutationally reversible. (vi) Simple leaves in model plants such as Arabidopsis thaliana despite overexpression of KNOX1 orthologues do not become compound. (v) All forms of leaves, including simple leaf, probably have origins in a gene regulatory network of the kind present in P. sativum.
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Interaction between cochleata and Stipule-reduced mutations results in exstipulate hypertrophied leaves in Pisum sativum L.
Indian journal of experimental biology, 2013Co-Authors: Arvind Kumar, Vishakha Sharma, Sushil KumarAbstract:In the wild type P. sativum, each of the adult plant stem nodes, bears a pair of sessile foliaceous Stipules and a petiolated unipinnately compound leaf of 4 to 6 leaflets and 7-9 tendrils. The Stipule-reduced (st) and cochleata (coch) single null mutants and coch st double null mutant differ fom the wild type in respectively having sessile Stipules of much reduced size, petiolated simple and/or compound leaf-like Stipules and no Stipules. It is also known that coch leaves are somewhat bigger than st and wild type leaves. Here, pleiotropic phenotype of coch st double mutant was investigated. The morphologies of Stipules and leaf were quantified in the field grown plants and microcultured shoots, latter in the presence and absence of gibberellic acid and N-1-naphthylphthalamic acid. The observations showed that as compared to the corresponding plants or shoots of COCH ST (WT) genotype, (a) coch st plants bore leaves in which all the organs were hypertrophied; (b) full complement of leaflets and 3-5 tendrils were formed on leaf; (c) the microcultured coch st shoots were taller despite lower number of nodes, and (d) they also produced leaves in which all the organs were bigger and the ratio of leaflets/tendrils was higher. It was concluded that in coch st double mutant (a) ST function is essential for Stipule primordium differentiation, in the absence of COCH function and (b) absence of negative feedback loops between simple Stipules and compound leaf for metabolite utilization allows hypertrophied growth in leaves.
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Genetic interaction and mapping studies on the leaflet development (lld) mutant in Pisum sativum
Journal of Genetics, 2012Co-Authors: Sushil Kumar, Vishakha Sharma, Swati Chaudhary, Arvind Kumar, Raghvendra Kumar Mishra, Renu KumariAbstract:In Pisum sativum , the completely penetrant leaflet development ( lld ) mutation is known to sporadically abort pinnae suborgans in the unipinnate compound leaf. Here, the frequency and morphology of abortion was studied in each of the leaf suborgans in 36 genotypes and in presence of auxin and gibberellin, and their antagonists. Various lld genotypes were constructed by multifariously recombining lld with a coch homeotic Stipule mutation and with af , ins , mare , mfp , tl and uni-tac leaf morphology mutations. It was observed that the suborgans at all levels of pinna subdivisions underwent lld -led abortion events at different stages of development. As in leafblades, lld aborted the pinnae in leaf-like compound coch Stipules. The lld mutation interacted with mfp synergistically and with other leaf mutations additively. The rod-shaped and trumpet-shaped aborted pea leaf suborgans mimicked the phenotype of aborted leaves in HD-ZIP-III-deficient Arabidopsis thaliana mutants. Suborganwise aborted morphologies in lld gnotypes were in agreement with basipetal differentiation of leaflets and acropetal differentiation in tendrils. Altogether, the observations suggested that LLD was the master regulator of pinna development. On the basis of molecular markers found linked to lld , its locus was positioned on the linkage group III of the P. sativum genetic map.
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Roles of Stipules Include Determination of Flowering Time and Pod Harvest Index in Garden Pea Grain Legume Pisum sativum
National Academy Science Letters, 2012Co-Authors: Vishakha Sharma, Sushil KumarAbstract:Stipules are known to photosynthesize and provide protection to the organs differentiating at the apex, associated leaf and branch-bud and inflorescence in the axil of leaf. Stipules are expected to affect the bearer plant in multiple ways. To reveal the relative roles of Stipules and leaves in Pisum sativum, the growth and development properties of leaf+ Stipule− (L+S−), leaf− Stipule+ (L−S+) and leaf+ Stipule+ (L+S+) plants were compared. The L−S+ and L+S− plants were respectively obtained by surgically removing the leaves and Stipules as soon as formed from the post-embryonic nodes of the genetically wild type Stipule and leaf bearing plants. The three sets of plants were arranged in a completely randomized design and sampled at the near harvest time for the phenotypic quantitation of ten primary and six secondary traits. The L−S+ and L+S− plants were later in flowering, scarce in branching and total number of nodes, lower in biomass and bore pods in lesser numbers than L+S+ plants. The biomass allocation to leaves and/or stems was higher in L+S−and L−S+ plants as compared to L+S+ plants in which pods were the principal organs of biomass deposition. The observations allowed the conclusions that both Stipules and leaves determine the flowering time and presence of Stipules maximizes biomass allocation to pods and in turn the harvest index.
Arvind Kumar Kumar - One of the best experts on this subject based on the ideXlab platform.
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Auxin transport inhibitor induced low complexity petiolated leaves and sessile leaf-like Stipules and architectures of heritable leaf and Stipule mutants in Pisum sativum suggest that its simple lobed Stipules and compound leaf represent ancestral fo
Journal of Genetics, 2013Co-Authors: Arvind Kumar Kumar, Mali Ram Hindala, Vishakha Sharma, Moinuddin Khan, Sushil KumarAbstract:In angiosperms, leaf and Stipule architectures are inherited species-specific traits. Variation in leaf and Stipule sizes, and forms result from the interaction between abiotic and biotic stimuli, and gene regulatory network(s) that underlie the leaf and Stipule developmental programme(s). Here, correspondence between variation in leaf and Stipule architectures described for extant angiosperms and that induced mutationally and by imposition of stress in model angiosperm species, especially in Pisum sativum, was detected. Following inferences were drawn from the observations. (i) Several leaf forms in P. sativum have origin in fusion of Stipule and leaf primordia. Perfoliate (and amplexicaul and connate) simple sessile leaves and sessile adnate leaves are the result of such primordial fusions. Reversal of changes in the gene regulatory network responsible for fusion products are thought to restore original Stipule and leaf conditions. (ii) Compound leaf formation in several different model plants, is a result of promotion of pathways for such condition by gene regulatory networks directed by KNOX1 and LEAFY transcription factors or intercalation of the gene networks directed by them. (iii) Gene regulatory network for compound leaves in P. sativum when mutated generates highly complex compound leaves on one hand and simple leaves on other hand. These altered conditions are mutationally reversible. (vi) Simple leaves in model plants such as Arabidopsis thaliana despite overexpression of KNOX1 orthologues do not become compound. (v) All forms of leaves, including simple leaf, probably have origins in a gene regulatory network of the kind present in P. sativum.
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Pisum sativum wild-type and mutant Stipules and those induced by an auxin transport inhibitor demonstrate the entire diversity of laminated Stipules observed in angiosperms.
Protoplasma, 2012Co-Authors: Arvind Kumar Kumar, Vishakha Sharma, Moinuddin Khan, Bhumi Nath Tripathi, Sushil KumarAbstract:About a quarter of angiosperm species are stipulate. They produce Stipule pairs at stem nodes in association with leaves. Stipule morphology is treated as a species-specific characteristic. Many species bear Stipules as laminated organs in a variety of configurations, including laterally free large foliaceous, small, or wholly leaf-like Stipules, and as fused intrapetiolar, opposite, ochreate or interpetiolar Stipules. In Pisum sativum, the wild-type and Stipule-reduced and cochleata mutants are known to form free large, small, and leaf-like Stipules, respectively. Auxin controls initiation and development of plant organs and perturbations in its availability and distribution in the meristems, caused by auxin transport inhibitor(s) (ATIs), lead to aberrations in leaf development. The effect(s) of ATI(s) on Stipule development are unexplored. To study the effect of the ATI 1-N-naphthylphthalamic acid (NPA) on Stipule morphogenesis, P. sativum explants were grown in vitro in presence of a sublethal concentration of NPA. The NPA-treated shoots produced fused Stipules of all the different types described in angiosperms. The observations indicate that (a) the gene sets for Stipule differentiation may be common in angiosperms and (b) the interspecies Stipule architectural differences are due to mutations, affecting gene expression or activity that got selected in the course of evolution.
Vicente Balanzà - One of the best experts on this subject based on the ideXlab platform.
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Identification of Stipules reduced, a leaf morphology gene in pea (Pisum sativum).
The New phytologist, 2018Co-Authors: Carol Moreau, Julie M.i. Hofer, Morgane P Eléouët, Andrey A. Sinjushin, Mike Ambrose, Kirsten P. Skøt, Tina Blackmore, Martin T. Swain, Matthew J. Hegarty, Vicente BalanzàAbstract:Pea (Pisum sativum) is one of relatively few genetically amenable plant species with compound leaves. Pea leaves have a variety of specialized organs: leaflets, tendrils, pulvini and Stipules, which enable the identification of mutations that transform or affect distinct parts of the leaf. Characterization of these mutations offers insights into the development and evolution of novel leaf traits. The previously characterized morphological gene Cochleata, conferring Stipule identity, was known to interact with Stipules reduced (St), which conditions Stipule size in pea, but the St gene remained unknown. Here we analysed Fast Neutron irradiated pea mutants by restriction site associated DNA sequencing. We identified St as a gene encoding a C2H2 zinc finger transcription factor that is regulated by Cochleata. St regulates both cell division and cell expansion in the Stipule. Our approach shows how systematic genome-wide screens can be used successfully for the analysis of traits in species for which whole genome sequences are not available.
P. Dhanasekar - One of the best experts on this subject based on the ideXlab platform.
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Morphological Features and Inheritance of Foliaceous Stipules of Primary Leaves in Cowpea (Vigna unguiculata)
Annals of botany, 2004Co-Authors: R. N. Pandey, P. DhanasekarAbstract:• Background and Aims The presence of connate foliaceous Stipules of primary leaves and their inheritance in cowpea (Vigna unguiculata) genotype {"type":"entrez-nucleotide","attrs":{"text":"EC394736","term_id":"109284246","term_text":"EC394736"}}EC394736 is reported for the first time. • Methods The development of foliaceous Stipules (FS) and their persistence were examined throughout the growth and developmental stages of the plants of the genotype {"type":"entrez-nucleotide","attrs":{"text":"EC394736","term_id":"109284246","term_text":"EC394736"}}EC394736. The shape, size, colour, texture and other parameters were examined in the field during the period 15–50 d after sowing. The area of FS was measured using image analysis software. The inheritance of FS was studied by making a cross between the genotype {"type":"entrez-nucleotide","attrs":{"text":"EC394763","term_id":"109284295","term_text":"EC394763"}}EC394763 with rudimentary Stipules (RS) and the genotype {"type":"entrez-nucleotide","attrs":{"text":"EC394736","term_id":"109284246","term_text":"EC394736"}}EC394736, which has connate foliaceous Stipules of primary leaves. The presence or absence of FS in plants of the F1, F2 and F3 generations was recorded. • Key Results The Stipules developed along with the primary leaves in the genotype {"type":"entrez-nucleotide","attrs":{"text":"EC394736","term_id":"109284246","term_text":"EC394736"}}EC394736. One Stipule of each primary leaf fused with the adjacent Stipule of the other primary leaf forming a foliaceous structure. These Stipules persisted on the plants for >50 d, even after the primary leaves had withered off. The F1 plants showed an absence of FS indicating the rudimentary Stipules to be dominant over foliaceous Stipules. The F2 segregation into 15 (RS) : 1 (FS) indicated that duplicate recessive genes controlled the presence of the FS. This was confirmed from the segregation pattern in the F3 generation. • Conclusions The presence of FS is a unique feature in cowpea genotype {"type":"entrez-nucleotide","attrs":{"text":"EC394736","term_id":"109284246","term_text":"EC394736"}}EC394736 and duplicate recessive genes govern it. The FS can be used as a morphological marker for identification of cowpea varieties.