International Master Program of Agriculture, National Chung Hsing University, Taichung, 402, Taiwan.
Department of Agronomy, National Chung Hsing University, Taichung, 402, Taiwan.
BMC Plant Biol. 2023 Jul 27;23(1):372. doi: 10.1186/s12870-023-04380-y.
The increased frequency of heavy rains in recent years has led to submergence stress in rice paddies, severely affecting rice production. Submergence causes not only hypoxic stress from excess water in the surrounding environment but also osmotic stress in plant cells. We assessed physiological responses and Ethylene-Response AP2/ERF Factor regulation under submergence conditions alone and with ionic or nonionic osmotic stress in submergence-sensitive IR64 and submergence-tolerant IR64-Sub1 Indica rice cultivars.
Our results indicate that both IR64 and IR64-Sub1 exhibited shorter plant heights and root lengths under submergence with nonionic osmotic stress than normal condition and submergence alone. IR64-Sub1 seedlings exhibited a significantly lower plant height under submergence conditions alone and with ionic or nonionic osmotic stress than IR64 cultivars. IR64-Sub1 seedlings also presented lower malondialdehyde (MDA) concentration and higher survival rates than did IR64 seedlings after submergence with ionic or nonionic osmotic stress treatment. Sub1A-1 affects reactive oxygen species (ROS) accumulation and antioxidant enzyme activity in rice. The results also show that hypoxia-inducible ethylene response factors (ERF)-VII group and alcohol dehydrogenase 1 (ADH1) and lactate dehydrogenase 1 (LDH1) genes exhibited different expression levels under nonionic or ionic osmotic stress during submergence on rice.
Together, these results demonstrate that complex regulatory mechanisms are involved in responses to the aforementioned forms of stress and offer new insights into the effects of submergence and osmotic stress on rice.
近年来，降雨量的增加导致稻田被淹没，严重影响了水稻的产量。淹没不仅会导致周围环境水分过多引起的缺氧胁迫，还会导致植物细胞的渗透胁迫。我们评估了单独在淹没条件下以及在离子或非离子渗透胁迫下，在淹没敏感型 IR64 和淹没耐受型 IR64-Sub1 籼稻品种中，生理响应和乙烯应答 AP2/ERF 因子的调节。
我们的结果表明，IR64 和 IR64-Sub1 在非离子渗透胁迫下的淹没条件下，其株高和根长均比正常条件和单独淹没时短。IR64-Sub1 幼苗在单独淹没和离子或非离子渗透胁迫条件下的株高明显低于 IR64 品种。IR64-Sub1 幼苗在离子或非离子渗透胁迫处理后的 MDA 浓度较低，存活率较高。Sub1A-1 影响水稻中活性氧（ROS）的积累和抗氧化酶活性。结果还表明，在淹水期间，非离子或离子渗透胁迫下，缺氧诱导的乙烯应答因子（ERF）-VII 组和醇脱氢酶 1（ADH1）和乳酸脱氢酶 1（LDH1）基因的表达水平不同。
综上所述，这些结果表明，复杂的调控机制参与了对上述形式胁迫的反应，并为淹没和渗透胁迫对水稻的影响提供了新的见解。
