Liu Zijie, Zheng Xingfei, Yang Dabing, Li Lanzhi, Yin Hexing
Hunan Engineering & Technology Research Center for Agricultural Big Data Analysis & Decision-Making, College of Plant Protection, Hunan Agricultural University, Changsha, China.
Hubei Key Laboratory of Food Crop Germplasm and Genetic Improvement, Food Crop Institute, Hubei Academy of Agricultural Sciences, Wuhan, China.
Front Plant Sci. 2025 Apr 22;16:1562718. doi: 10.3389/fpls.2025.1562718. eCollection 2025.
Thioredoxins (TRX) are redox-active proteins critical for plant stress adaptation. As a TRX family member, nucleoredoxin (NRX) maintains drought-induced redox homeostasis, yet its genome-wide characterization in rice remains uninvestigated.
Using HMMER3.0 (E-value <1e-5) and TBtools, we identified OsNRX genes across three rice varieties (Minghui63, Nipponbare, 9311). Conserved domains were verified by SMART/CDD, while promoter cis-elements were systematically predicted with PlantCARE. Tissue-specific expression patterns were analyzed using RiceXPro data, and drought responses were quantified via qRT-PCR in drought-tolerant (Jiangnong Zao 1B) versus sensitive (TAISEN GLUTINOUS YU 1157) varieties under PEG6000 stress.
Ten OsNRX genes were classified into three subfamilies (NRX1/NRX2/NRX3) exhibiting conserved domain architectures. Promoter analysis identified abundant stress-responsive elements (ABRE, MBS) and phytohormone signals (ABA/JA/SA). Tissue-specific expression profiles revealed NRX1a dominance in roots/hulls, versus NRX1b/NRX2 enrichment in endosperm. Drought stress triggered rapid OsNRX upregulation (20-53-fold within 3-6h), with tolerant varieties showing earlier NRX2 activation than sensitive counterparts.
OsNRX genes exhibit dynamic drought-responsive regulation, while their spatiotemporal expression in glumes, embryos, and endosperm suggests potential dual roles in stress adaptation and grain development. These results provide molecular targets for improving drought resilience in rice breeding.
硫氧还蛋白（TRX）是对植物胁迫适应性至关重要的氧化还原活性蛋白。作为TRX家族成员，核硫氧还蛋白（NRX）维持干旱诱导的氧化还原稳态，但其在水稻中的全基因组特征仍未得到研究。
使用HMMER3.0（E值<1e-5）和TBtools，我们在三个水稻品种（明恢63、日本晴、9311）中鉴定了OsNRX基因。通过SMART/CDD验证保守结构域，同时使用PlantCARE系统预测启动子顺式元件。利用RiceXPro数据分析组织特异性表达模式，并通过qRT-PCR在PEG6000胁迫下的耐旱品种（江农早1B）和敏感品种（泰森糯玉1157）中定量干旱响应。
十个OsNRX基因被分为三个亚家族（NRX1/NRX2/NRX3），呈现出保守的结构域架构。启动子分析鉴定出丰富的胁迫响应元件（ABRE、MBS）和植物激素信号（ABA/JA/SA）。组织特异性表达谱显示NRX1a在根/颖壳中占主导地位，而NRX1b/NRX2在胚乳中富集。干旱胁迫引发OsNRX快速上调（3-6小时内上调20-53倍），耐旱品种比敏感品种更早激活NRX2。
OsNRX基因表现出动态的干旱响应调控，而它们在颖片、胚和胚乳中的时空表达表明在胁迫适应和籽粒发育中可能具有双重作用。这些结果为提高水稻育种中的耐旱性提供了分子靶点。
