Effects of exogenous abscisic acid and gibberellic acid on pre-maturity α-amylase formation in wheat grains

Kondhare, Kirtikumar R.; Kettlewell, P. S.; Farrell, Aidan D.; Hedden, Peter

doi:10.1007/s10681-012-0706-0

Cited by 21 publications

(22 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…At 14 DAP, a clear improvement of in vitro precocious germination was observed only in PBA Pearl with +100 µM GA 3 . The enhancing effect of exogenous GA on precocious seed germination in pea is consistent with experiments showing promotion of α-amylase synthesis in germinating wheat seeds treated with GA 3 (Hader et al, 2003; Kondhare et al, 2012).…”

Section: Discussionsupporting

confidence: 88%

Expression Patterns of Key Hormones Related to Pea (Pisum sativum L.) Embryo Physiological Maturity Shift in Response to Accelerated Growth Conditions

et al. 2019

View full text Add to dashboard Cite

Protocols have been proposed for rapid generation turnover of temperate legumes under conditions optimized for day-length, temperature, and light spectra. These conditions act to compress time to flowering and seed development across genotypes. In pea, we have previously demonstrated that embryos do not efficiently germinate without exogenous hormones until physiological maturity is reached at 18 days after pollination (DAP). Sugar metabolism and moisture content have been implicated in the modulation of embryo maturity. However, the role of hormones in regulating seed development is poorly described in legumes. To address this gap, we characterized hormonal profiles (IAA, chlorinated auxin [4-Cl-IAA], GA20, GA1, and abscisic acid [ABA]) of developing seeds (10–22 DAP) from diverse pea genotypes grown under intensive conditions optimized for rapid generation turnover and compared them to profiles of equivalent samples from glasshouse conditions. Growing plants under intensive conditions altered the seed hormone content by advancing the auxin, gibberellins (GAs) and ABA profiles by 4 to 8 days, compared with the glasshouse control. Additionally, we observed a synchronization of the auxin profiles across genotypes. Under intensive conditions, auxin peaks were observed at 10 to 12 DAP and GA20 peaks at 10 to 16 DAP, indicative of the end of embryo morphogenesis and initiation of seed desiccation. GA1 was detected only in seeds harvested in the glasshouse. These results were associated with an acceleration of embryo physiological maturity by up to 4 days in the intensive environment. We propose auxin and GA profiles as reliable indicators of seed maturation. The biological relevance of these hormonal fluctuations to the attainment of physiological maturity, in particular the role of ABA and GA, was investigated through the study of precocious in vitro germination of seeds 12 to 22 DAP, with and without exogenous hormones. The extent of sensitivity of developing seeds to exogenous ABA was strongly genotype-dependent. Concentrations between 5 and 10 µM inhibited germination of seeds 18 DAP. Germination of seeds 12 DAP was enhanced 2.5- to 3-fold with the addition of 125 µM GA3. This study provides further insights into the hormonal regulation of seed development and in vitro precocious germination in legumes and contributes to the design of efficient and reproducible biotechnological tools for rapid genetic gain.

show abstract

Section: Discussionsupporting

confidence: 88%

Expression Patterns of Key Hormones Related to Pea (Pisum sativum L.) Embryo Physiological Maturity Shift in Response to Accelerated Growth Conditions

et al. 2019

View full text Add to dashboard Cite

show abstract

“…On the basis of the microarray analysis, genes related to GA would appear to be altered earlier (20 DPA) than the genes related to ABA (at 23 DPA), suggesting that changes in GAs would appear before changes in ABA. In addition to the changes in endogenous hormones reported in this study, earlier studies have also highlighted the possibility that LMA expression may also be associated with increased GA sensitivity in LMA-prone lines compared with non-LMA lines (Mares and Mrva, 2008a;Kondhare et al, 2012). A detailed hormonal profiling and analysis of GA signaling components during grain development is required to resolve these critical questions.…”

Section: Hormonal Changes Associated With Lmamentioning

confidence: 73%

Genetic, Hormonal, and Physiological Analysis of Late Maturity α-Amylase in Wheat

et al. 2013

View full text Add to dashboard Cite

Late maturity a-amylase (LMA) is a genetic defect that is commonly found in bread wheat (Triticum aestivum) cultivars and can result in commercially unacceptably high levels of a-amylase in harvest-ripe grain in the absence of rain or preharvest sprouting. This defect represents a serious problem for wheat farmers, and apart from the circumstantial evidence that gibberellins are somehow involved in the expression of LMA, the mechanisms or genes underlying LMA are unknown. In this work, we use a doubled haploid population segregating for constitutive LMA to physiologically analyze the appearance of LMA during grain development and to profile the transcriptomic and hormonal changes associated with this phenomenon. Our results show that LMA is a consequence of a very narrow and transitory peak of expression of genes encoding high-isoelectric point a-amylase during grain development and that the LMA phenotype seems to be a partial or incomplete gibberellin response emerging from a strongly altered hormonal environment.

show abstract

“…By contrast, Kondhare et al (2014) reported both GA1 and GA3 in extracts from whole grains of LMA genotypes, however, it is possible their results may have been confounded by the use of whole grain rather than the specific grain fraction, aleurone, involved in LMA expression. Nevertheless, several lines of evidence are consistent with the involvement of GA in LMA expression: the wellestablished signal transduction pathway in grain aleurone involving GA, DELLA (Rht in wheat) and a GAmyb that triggers a-amylase synthesis; the effect of the GA-insensitive mutants, Rht1, Rht2 and Rht3, in reducing the expression of LMA; and stimulation of a-amylase synthesis in LMA-prone cultivars following application of exogenous GA during grain development (Kondhare et al 2012). The latter report is open to some question given that only total a-amylase was measured and it is well established that application of exogenous GA may stimulate expression of both low and high pI a-amylase.…”

Section: Expression Of Lmamentioning

confidence: 83%

Wheat grain preharvest sprouting and late maturity alpha-amylase

Mares

Mrva

2014

Planta

129

176

View full text Add to dashboard Cite

Preharvest sprouting (PHS) and late maturity α-amylase (LMA) are the two major causes of unacceptably high levels of α-amylase in ripe wheat grain. High α-amylase activity in harvested grain results in substantially lower prices for wheat growers and at least in the case of PHS, is associated with adverse effects on the quality of a range of end-products and loss of viability during storage. The high levels of α-amylase are reflected in low falling number, the internationally accepted measure for grain receival and trade. Given the significant losses that can occur, elimination of these defects remains a major focus for wheat breeding programs in many parts of the world. In addition, the genetic, biochemical and molecular mechanisms involved in the control of PHS and LMA as well as the interactions with environmental factors have attracted a sustained research interest. PHS and LMA are independent, genetically controlled traits that are strongly influenced by the environment, where the effects of particular environmental factors vary substantially depending on the stage of grain development and ripening. This review is a summary and an assessment of results of recent research on these important grain quality defects.

show abstract

Effects of exogenous abscisic acid and gibberellic acid on pre-maturity α-amylase formation in wheat grains

Cited by 21 publications

References 26 publications

Expression Patterns of Key Hormones Related to Pea (Pisum sativum L.) Embryo Physiological Maturity Shift in Response to Accelerated Growth Conditions

Expression Patterns of Key Hormones Related to Pea (Pisum sativum L.) Embryo Physiological Maturity Shift in Response to Accelerated Growth Conditions

Genetic, Hormonal, and Physiological Analysis of Late Maturity α-Amylase in Wheat

Wheat grain preharvest sprouting and late maturity alpha-amylase

Contact Info

Product

Resources

About