College of Agronomy, Northwest A&F University, Yangling, Shaanxi, 712100, People's Republic of China.
Plant Physiol Biochem. 2022 Jan 1;170:255-265. doi: 10.1016/j.plaphy.2021.12.004. Epub 2021 Dec 8.
Drought stress is an important factor that affects crop yields and quality. E3 ubiquitin ligase has crucial roles in the responses to abiotic stresses. However, few studies have investigated the role of E3 ubiquitin ligase during drought stress in wheat. In this study, we cloned and identified the orthologous gene of Oryza sativa Salt-, ABA- and Drought-Induced RING Finger Protein 1 (OsSADR1) in wheat (Triticum aestivum L.) called TaSADR1. TaSADR1 encodes a protein containing 486 amino acids with a C3HC4 type RING finger conserved domain at the N-terminal. We confirmed that TaSADR1 has an E3 ubiquitin ligase activity and it is located in the nucleus. High expression of TaSADR1 was induced by treatment with PEG6000 and abscisic acid (ABA). TaSADR1-overexpressing transgenic Arabidopsis plants exhibited decreased drought tolerance. Under drought stress, compared with the wild-type (WT) lines, TaSADR1-overexpressing transgenic Arabidopsis lines had lower proline and chlorophyll contents, and antioxidant enzyme activities (superoxide dismutase, peroxidase, and catalase), whereas the water loss rate, malondialdehyde content, and relative electrolyte leakage were higher. In addition, the overexpressing transgenic Arabidopsis lines were more sensitive to mannitol and ABA treatment at seed germination and during seedling growth. The expression levels of genes related to stress were downregulated under drought conditions in the transgenic plants. Our results demonstrate that TaSADR1 may negatively regulate drought stress responses by regulating the expression of stress-related genes.
干旱胁迫是影响作物产量和品质的重要因素。E3 泛素连接酶在非生物胁迫响应中起着关键作用。然而，目前关于 E3 泛素连接酶在小麦干旱胁迫中的作用研究较少。本研究克隆并鉴定了小麦同源基因 Oryza sativa Salt-、ABA-和 Drought-Induced RING Finger Protein 1（OsSADR1），命名为 TaSADR1。TaSADR1 编码一个含有 486 个氨基酸的蛋白质，其 N 端含有 C3HC4 型 RING 指保守结构域。我们证实 TaSADR1 具有 E3 泛素连接酶活性，并且位于细胞核内。PEG6000 和脱落酸（ABA）处理可诱导 TaSADR1 高表达。TaSADR1 过表达的拟南芥转基因植株表现出抗旱性降低。在干旱胁迫下，与野生型（WT）系相比，TaSADR1 过表达的拟南芥转基因系脯氨酸和叶绿素含量较低，抗氧化酶活性（超氧化物歧化酶、过氧化物酶和过氧化氢酶）较低，而失水率、丙二醛含量和相对电解质渗出率较高。此外，在种子萌发和幼苗生长期间，过表达的转基因拟南芥系对甘露醇和 ABA 处理更敏感。在转基因植物中，与干旱条件相关的基因表达水平下调。我们的结果表明，TaSADR1 可能通过调节与胁迫相关的基因表达来负调控干旱胁迫响应。
