The Role of Hormones in Photosynthate Partitioning and Seed Filling

Brenner, Mark L.; Cheikh, Nordine

doi:10.1007/978-94-011-0473-9_30

Cited by 85 publications

(45 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Presence of strong relationships indicated that ABA may be involved in the transport of the assimilates under drought stress. This is concurrent with a previous report which showed that ABA is an important regulator in enhancing drought tolerance of plants (Liu & Baird 2004, Manavella et al 2006 or in transport of assimilates (Brenner & Cheikh 1995, Yang et al 1999.…”

Section: Discussionsupporting

confidence: 88%

Effects of varied water regimes on root length, dry matter partitioning and endogenous plant growth regulators in sunflower (Helianthus annuusL.)

Rauf

Sadaqat

2007

Journal of Plant Interactions

View full text Add to dashboard Cite

A field experiment was conducted to quantify the effect of varied water regimes on root length, partitioning of dry matter and plant growth regulators by using sunflower genotypes differing in maturity and drought tolerance. Significant depressing effect of drought stress was evident on traits (i.e., reproductive dry matter, leaf area index and cytokinin concentrations in leaves). However, root/shoot, reproductive/vegetative ratios and Abscisic acid (ABA) concentration were found to increase under drought stress. Drought stress also changed the dry matter accumulation pattern of genotypes. In most cases it reduced the days to reach the maximum peak showing early senescence. ABA was identified as a multi-functional plant growth regulator under drought stress, causing early senescence of plants and translocation of assimilates to the roots and reproductive part while root growth under drought stress was explained by the indole-acetic acid (IAA) concentrations. Maintaining higher cytokinin contents were involved in accumulation of higher reproductive dry matter under drought stress. Although ABA and IAA were both involved in the development of defense responses during the adaptation and survival to drought stress but higher productivity under drought stress was only realized through maintaining higher cytokinin contents.

show abstract

Section: Discussionsupporting

confidence: 88%

Effects of varied water regimes on root length, dry matter partitioning and endogenous plant growth regulators in sunflower (Helianthus annuusL.)

Rauf

Sadaqat

2007

Journal of Plant Interactions

View full text Add to dashboard Cite

show abstract

“…It has been proposed that CK controls seed size by influencing cell number in very young, developing seeds. Increased cell number would enhance storage capacity (Morris et al, 1993;Brenner and Cheikh, 1995). Studies of corn, wheat, and rice (Morris et al, 1993) show that CK content is highest during developmental stages that encompass periods of the most rapid nuclear and cell division of the endosperm.…”

Section: Cis-isomers Of Cytokinin Predominate In Chickpea Seedsmentioning

confidence: 99%

“…Seeds have turned out to be a rich source of CK, and in the past 30 years investigators have described a range of different CK from seed tissues (van Staden et al, 1982). This may reflect their relatively high levels in seeds (van Staden et al, 1982), a status that is believed to indicate a role for CK in establishing developing seeds as strong assimilate sinks (Brenner and Cheikh, 1995). Despite a vast literature concerning the occurrence, form, and significance of CK in plant development, the nature and site(s) of their synthesis is yet to be established.…”

mentioning

confidence: 99%

cis -Isomers of Cytokinins Predominate in Chickpea Seeds throughout Their Development1

Emery

Leport²,

Barton³

et al. 1998

Plant Physiology

108

View full text Add to dashboard Cite

Trans-isomers of cytokinins (CK) are thought to predominate and have greater biological activity than corresponding cis-isomers in higher plants. However, this study demonstrates a system within which the predominant CK are cis-isomers. CK were measured at four developmental stages in developing chickpea (Cicer arietinum L. cultivar Kaniva) seeds by gas chromatography-mass spectrometry. Concentrations were highest at an early endospermic fluid stage and fell considerably when the cotyledons expanded. Seed tissues were the source for isolation of the first naturally occurring CK, trans-Z (Miller, 1961;Letham, 1963). Seeds have turned out to be a rich source of CK, and in the past 30 years investigators have described a range of different CK from seed tissues (van Staden et al., 1982). This may reflect their relatively high levels in seeds (van Staden et al., 1982), a status that is believed to indicate a role for CK in establishing developing seeds as strong assimilate sinks (Brenner and Cheikh, 1995). Despite a vast literature concerning the occurrence, form, and significance of CK in plant development, the nature and site(s) of their synthesis is yet to be established. In fact, Holland (1997) recently proposed that CK are not formed by plants at all but rather by bacterial symbionts that colonize plant tissues. Although there is good evidence for the transfer of CK synthesized by Rhizobium in legume nodules (Upadhyaya et al., 1991), a role for bacteria in providing CK to roots or shoot organs needs to be investigated more thoroughly. Because unequivocal evidence for a plant isopentenyl transferase is lacking, a persistent hypothesis, which has recently been reviewed (Prinsen et al., 1997), is that the free CK in plants are not synthesized de novo but are released during tRNA turnover.Z, [9R-MP]Z, and [9R]Z have an unsaturated isopentenyl side chain that can exist in the cis or trans conformation. The cis-isomer occurs when the hydroxyl group of the isopentenyl side chain is oriented toward the N-1 position of the purine ring, whereas in the trans-isomer the hydroxyl group is oriented away from the purine ring (Korszun et al., 1989; Fig. 1). The trans-isomers of [9R]Z and Z are by far the more commonly reported forms and are considered the predominant isomers in higher plants (McGaw and Burch, 1995;Prinsen et al., 1997). Systems in which the existence of cis-CK can be demonstrated unequivocally would be significant for two reasons. First, because cis-CK show much lower activity than trans-CK in bioassays (Kaminek, 1982) and their interconversion may constitute a mechanism for reducing CK bioactivity in vivo. Second, cis-CK provide evidence for the hypothesis that the free CK pool in higher plants may be at least partially derived from the breakdown of tRNA. The major criticism of this hypothesis has been the structural distinctness between tRNA-bound CK and free-pool CK (Letham and Palni, 1983;McGaw and Burch, 1995;Prinsen et al., 1997

show abstract

“…This di¡erential provisioning could occur if carbon demand or hormones produced by the developing endosperm and zygotes determine the quantity of resources allocated by the maternal plant (Brenner 1987). This is supported by our observed di¡erences in seed mass and germination date for seeds sired by the two types of donors: ¢rst-fertilized seeds, regardless of whether they were sired by slow-or fastgrowing pollen, were consistently, though non-signi¢-cantly, heavier than later-fertilized seeds and germinated signi¢cantly earlier.…”

Section: Resultsmentioning

confidence: 99%

Why fast-growing pollen tubes give rise to vigorous progeny: the test of a new mechanism

Delph

Weinig

Sullivan

1998

Proc. R. Soc. Lond. B

View full text Add to dashboard Cite

A positive correlation between the speed of pollen tube growth and the quality of the resulting progeny in several species of £owering plants has traditionally been explained as being caused by an overlap in gene expression between gametophytes and sporophytes. We experimentally manipulated the pollen tube growth rates of pollen donors, such that the genotype controlling the rate was uncoupled from the phenotype, to test the alternative hypothesis that the correlation arises because ovules fertilized early are better provisioned by the maternal plant than later-fertilized ovules. Crosses using Silene vulgaris individuals bearing distinctive genetic markers revealed a correlation between the order of fertilization by pollen grains and vigour of the resulting sporophytes, which was independent of the speed of growth of the pollen tubes. Seeds sired by donors with relatively fast-growing pollen germinated earlier and grew larger than those sired by slow-growing pollen when pollen from the two donors was applied simultaneously. Reversing the order of arrival in the ovary by placing slow-growing pollen on the styles earlier and closer to the ovary led to reverse results. These results suggest that di¡erential provisioning by the maternal plant can lead to di¡erences in progeny vigour following pollen competition.

show abstract

The Role of Hormones in Photosynthate Partitioning and Seed Filling

Cited by 85 publications

References 46 publications

Effects of varied water regimes on root length, dry matter partitioning and endogenous plant growth regulators in sunflower (Helianthus annuusL.)

Effects of varied water regimes on root length, dry matter partitioning and endogenous plant growth regulators in sunflower (Helianthus annuusL.)

cis -Isomers of Cytokinins Predominate in Chickpea Seeds throughout Their Development1

Why fast-growing pollen tubes give rise to vigorous progeny: the test of a new mechanism

Contact Info

Product

Resources

About