scholarly journals Influence of γ-irradiation on the expression of encoding ABA metabolism enzymes in barley embryos

2018 ◽  
Vol 16 (4) ◽  
pp. 85-89
Author(s):  
Sofia V. Bitarishvili ◽  
Vladimir S. Bondarenko ◽  
Stanislav A. Geras’kin

Background. Small doses of radiation stimulate the growth and development of plants including seed germination. ABA plays a key role not only in seed dormancy and germination but also in the regulation of adaptive reactions of plants. The aim of our work was to study the effect of γ-irradiation of barley seeds in a small doses on the expression of genes encoding ABA biosynthesis enzyme 9-cis-epoxycarotenoid dioxygenase (HvNCED1) and catabolism enzyme ABA 8’-hydroxylase (HvABA8’OH-1). Materials and Methods. The barley seeds were irradiated at dose range of 4–50 Gy at a dose rate of 60 Gy/h, the radiation source was 60Co. The study was carried out in the embryos within the first 30 hours after germination. Relative gene expression was investigated using real-time PCR (RT-PCR). Results. It was shown that γ-irradiation of barley seeds changes the expression of ABA biosynthesis and catabolism genes in all experimental groups. Conclusion. This alterations can lead to a decrease the ABA content under irradiation with stimulating doses and increase the biosynthesis of phytohormone under irradiation with inhibitory dose.

2020 ◽  
Author(s):  
Hong Lang ◽  
Yuting He ◽  
Jian Sun ◽  
Fengcheng Li ◽  
Dianrong Ma

Abstract Abstract Backgrounds: Weedy rice is one of the most severe weeds in paddy fields, strongly characterized by its high seed shattering level. Abscisic acid (ABA) serves as an abscission-accelerating signal and plays a critical role during abscission. However, mechanisms that link ABA and seed shattering remain elusive. In this study, we compared WR04-6 a shattering, and SN9816 non-shattering rice variety for genetic expression and ABA levels in the abscission zone (AZ) and the spikelet. Results : ABA content in WR04-6, particularly in AZ, was significantly higher than that in SN9816, and it increased remarkably prior to abscission. Transcriptomic analysis and qRT-PCR showed that the expression of NCED , the key gene in ABA biosynthesis, coincided with increased ABA content in AZ and increased significantly during the seed shattering process. Additionally, the expression of genes related biosynthesis and metabolism of IAA, GA, and ETH showed the greatest fold change. Phytohormone levels associated with ABA co-expression-prediction revealed a potential signal transduction network among plant hormones involved in regulating seed abscission. Conclusions: Altogether, our data strongly indicated that ABA contributes to seed shattering and appears to transiently cooperate with other hormones, triggering a hormone imbalance that leads to the downstream activation of AZ


2019 ◽  
Author(s):  
Muhammad Asad Ullah Asad ◽  
Fubiao Wang ◽  
Yu Ye ◽  
Xianyue Guan ◽  
Lujian Zhou ◽  
...  

Abstract Background: Both sucrose and abscisic acid (ABA) play pivotal role in the regulation of plant leaf senescence. However, the exact mechanism by which sugar starvation , ABA, and reactive oxygen species (ROS) interact with each other during leaf senescence remains largely unknown. In this study, the genotype-dependent alteration in temporal patterns of sugar concentration during leaf senescence and its relation to ABA metabolism and ROS generation were investigated by using the premature senescence of flag leaf ( psf ) mutant and its wild type. Results: Results showed that sugar starvation-induced leaf senescence was closely associated with the endogenous ABA concentration and ROS level in senescent leaves. Sugar starvation accelerated leaf senescence, concomitantly with the marked increase in ABA concentration and malonaldehyde (MDA) accumulation in detached leaves. Conversely, exogenous sugar treatment significantly suppressed the ABA concentration ad ROS level in detached leaves, thus leaf senescence was delayed by exogenous sugar supply. Pharmacological tests revealed that ABA biosynthesis inhibitor (NDGA) delayed the sugar starvation-induced leaf senescence, while ABA catabolism inhibitor (DNCZ) accelerated leaf senescence and significantly increased the endogenous ABA content in senescent leaves. For the expression patterns of ABA synthesis and catabolism related genes induced by sugar starvation, exogenous sucrose supply, NDGA and DNCZ. sugar starvation up-regulated the OsABA8ox1 transcript, while exogenous sucrose and NDGA down-regulated the transciptional expressions of OsNCED1 , OsNCED4 and OsNCED5 and OsABA8ox2 and OsABA8ox3 e by sugar starvation and DNCZ, while the transcript of was increased. Conclusion: Together, our results demonstrated that the rise in endogenous ABA content during sugar starvation-induced leaf senescence is mostly caused by the suppression of ABA catabolism, rather than the enhancement of ABA biosynthesis, and the expression of ABA metabolic genes determines the equilibrium between ABA biosynthesis and catabolism that eventually influence cross-talk between endogenous factors. The breaking for the equilibrium between ABA biosynthesis and catabolism was strongly responsible for sugar starvation-induced leaf senescence, which was resulted from the suppression of ABA catabolism, rather than the enhancement of ABA biosynthesis .


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