National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India.
National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India.
Plant Physiol Biochem. 2021 May;162:161-170. doi: 10.1016/j.plaphy.2021.02.042. Epub 2021 Mar 2.
Drought stress poses a severe threat to grain yield in rice. Our previous report demonstrated the role of OsJAZ9 in potassium homeostasis by modulating Jasmonic Acid (JA) signalling. While both potassium (K) and JA are known to have an important role in drought stress response, JA's repressor, i.e., JAZs' role in drought stress, remains elusive. Here we report that OsJAZ9 plays a critical role in rice water-deficit stress tolerance via influencing JA and ABA signalling. Overexpression of OsJAZ9 led to the enhanced ABA and JA levels. Our data further revealed that exogenous JA application antagonises the ABA-mediated inhibition of seed germination. Further, OsJAZ9 overexpression reduces leaf width and stomata density, leading to lower leaf transpiration rates than WT. This reduced transpiration and higher K content as osmoticum improved the water-deficit stress tolerance in OsJAZ9 overexpression lines. On the contrary, OsJAZ9 RNAi lines displayed enhanced sensitivity towards water-deficit stress. Our data provide new insights on the role of JA signalling repressors in rice response to water-deficit stress.
干旱胁迫严重威胁水稻的产量。我们之前的报告表明 OsJAZ9 通过调节茉莉酸（JA）信号在钾稳态中的作用。虽然钾（K）和 JA 都已知在干旱胁迫反应中起重要作用，但 JA 的抑制剂，即 JAZs 在干旱胁迫中的作用仍不清楚。在这里，我们报告说 OsJAZ9 通过影响 JA 和 ABA 信号通路在水稻水分胁迫耐受中发挥关键作用。过表达 OsJAZ9 导致 ABA 和 JA 水平升高。我们的数据进一步表明，外源 JA 的应用拮抗了 ABA 介导的种子萌发抑制。此外，OsJAZ9 的过表达减少了叶片宽度和气孔密度，导致比 WT 更低的叶片蒸腾速率。这种蒸腾减少和更高的 K 含量作为渗透物提高了 OsJAZ9 过表达系的水分胁迫耐受能力。相反，OsJAZ9 RNAi 系对水分胁迫表现出更高的敏感性。我们的数据为 JA 信号转导抑制剂在水稻应对水分胁迫中的作用提供了新的见解。
