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Titolo:
Genotypic differences in seed growth rates of Phaseolus vulgaris L. - I. General characteristics, seed coat factors and comparative roles of seed coats and cotyledons
Autore:
Thomas, M; Hetherington, L; Patrick, JW;
Indirizzi:
Univ Newcastle, Dept Biol Sci, Newcastle, NSW 2308, Australia Univ Newcastle Newcastle NSW Australia 2308 ewcastle, NSW 2308, Australia
Titolo Testata:
AUSTRALIAN JOURNAL OF PLANT PHYSIOLOGY
fascicolo: 2, volume: 27, anno: 2000,
pagine: 109 - 118
SICI:
0310-7841(2000)27:2<109:GDISGR>2.0.ZU;2-S
Fonte:
ISI
Lingua:
ENG
Soggetto:
VICIA-FABA L; SUCROSE TRANSPORT; CELLULAR PATHWAY; PHOTOSYNTHATE TRANSPORT; EFFLUX; EXPRESSION; METABOLISM; PLANTS; TURGOR; CELLS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Life Sciences
Citazioni:
38
Recensione:
Indirizzi per estratti:
Indirizzo: Patrick, JW Univ Newcastle, Dept Biol Sci, Newcastle, NSW 2308, Australia Univ Newcastle Newcastle NSW Australia 2308 W 2308, Australia
Citazione:
M. Thomas et al., "Genotypic differences in seed growth rates of Phaseolus vulgaris L. - I. General characteristics, seed coat factors and comparative roles of seed coats and cotyledons", AUST J PLAN, 27(2), 2000, pp. 109-118

Abstract

Developing seeds of four cultivars of Phaseolus vulgaris L., raised under glasshouse conditions, exhibited a 4-fold range in rates of storage productaccumulation by their cotyledons. These growth rate differences were established during seed expansion. Patterns of dry matter distribution were consistent with absolute growth rates of cotyledons being an inherent property of developing seeds and not limited by photoassimilate supply. Seed surfaceareas and cotyledon volumes exhibited a 3.2-fold cultivar difference and were the principal components contributing to cultivar variation in cotyledon absolute growth rates. The remaining cultivar variation was attributable to a 1.3-fold difference in dry matter fluxes, expressed on a seed surface area basis. Seed coats reflected these properties in terms of fluxes of drymatter released for cotyledon storage and surface areas supporting these fluxes. Seed coat surface areas correlated with estimates of total plasma membrane areas of ground parenchyma cells that are responsible for photoassimilate release. Cultivar differences in these membrane areas largely arose from variation in cell size. Coat turgor pressures correlated positively with dry matter fluxes imported into cotyledons. In contrast, sucrose concentration in bulk saps extracted from seed coats was identical across three cultivars but was positively related to growth rate in the remaining cultivar. Overall, these data suggested that cultivar dry matter fluxes were determined by variation in transport conductances for symplasmic movement through the post-sieve element pathway and for release across the plasma membranes of ground parenchyma cells. Comparable sucrose concentrations were found inseed apoplasmic saps across cultivars, and cultivar differences in absolute growth rates of in vitro cultured cotyledons were retained. Together, these observations support the conclusion that cotyledons intrinsically express genotypic variation in rates of dry matter transport comparable to those set independently by seed coats.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 12/07/20 alle ore 01:04:20