以γ射线诱变籼稻双科早(Oryza sativa subsp. indica cv. ‘Shuangkezao’)获得的早熟鲜绿突变体pe-1为实验材料, 在三叶期和分蘖期进行弱光胁迫, 探讨pe-1与野生型在形态特征、非生物胁迫相关酶活性及其调控基因表达量、叶绿素含量、叶绿体合成与降解及光形态建成相关基因表达对弱光响应的差异。结果表明, 与野生型相比, 弱光胁迫后, pe-1叶片黄化程度显著降低, 株高和叶面积显著增加; 三叶期和分蘖期的叶片中不同叶绿素含量变化不同。此外, pe-1叶绿素含量增加, 且其抗氧化应激反应相关酶过氧化氢酶(CAT)和过氧化物酶(POD)的活性及相关基因的表达量均高于野生型, 表明在弱光胁迫下pe-1活性氧清除能力增强, 适应能力更强。pe-1的光形态建成相关基因表达量高于野生型, 表明弱光处理下pe-1的光接收能力更强。综上, pe-1突变体具有抵御弱光胁迫的潜力, 该结果有助于耐弱光水稻品种的选育。

This study utilized the γ-ray-induced early-maturation, fresh-green mutant line pe-1 from indica rice as an experimental material. At the trilobal stage and the tillering stage, we observed differences in morphological characteristics between pe-1 and wild type. In addition, we measured the activity of antioxidant-related enzymes and their regulatory genes expression, chlorophyll content and chloroplast synthesis and degradation-related gene expression, and photomorphogenesis-related gene expression to detect the differences in the low light response between the pe-1 and wild type. The results showed that pe-1 exhibited less leaf yellowing, taller stature, and larger leaf area compared to wild type post-stress. The changes in chlorophyll content differed between leaves at the trilobal stage and the tillering stage. Additionally, pe-1 resulted in increased chlorophyll content and elevated levels of the stress-responsive enzymes catalase and peroxidase, as well as increased expression of related genes. This indicates enhanced reactive oxygen species sca- venging and stronger adaptability to adverse conditions under low light conditions. Moreover, pe-1 exhibited increased expression levels of genes associated with photomorphogenesis, indicating superior light perception ability under low light intensities. In summary, the pe-1 mutant shows immense potential for survival under low light stress, contributing to the breeding rice with low light tolerance.