Wany Aakanksha, Gupta Kapuganti Jagadis
a National Institute of Plant Genome Research, Aruna Asaf Ali Marg , New Delhi , India.
Plant Signal Behav. 2018 Feb 1;13(2):e1428515. doi: 10.1080/15592324.2018.1428515. Epub 2018 Feb 6.
In response to hypoxia, plant roots produce very high levels of nitric oxide. Recently, it was demonstrated that NO and ethylene both are essential for development of aerenchyma in wheat roots under hypoxia. Increased NO under hypoxia correlated with induction of NADPH oxidase gene expression, ROS production and lipid peroxidation in cortical cells. Tyrosine nitration was prominent in cells developing aerenchyma suggesting that NO and ROS play a key role in development of aerenchyma. However, the role of antioxidant genes during development of aerenchyma is not known, therefore, we checked gene expression of various antioxidants such as SOD1, AOX1A, APX and MnSOD at different time points after hypoxia treatment and found that expression of these genes elevated in 2 h but downregulated in 24 h where development of aerenchyma is prominent. Further, we found that plants growing under ammonium nutrition displayed delayed aerenchyma development. Taken together, new insights presented in this short communication highlighted additional regulatory role of antioxidants gene expression during aerenchyma development.
作为对缺氧的响应，植物根系会产生大量的一氧化氮。最近有研究表明，在缺氧条件下，一氧化氮和乙烯对于小麦根系通气组织的发育都是必不可少的。缺氧条件下一氧化氮水平的升高与NADPH氧化酶基因表达的诱导、活性氧的产生以及皮层细胞中的脂质过氧化作用相关。酪氨酸硝化作用在通气组织发育的细胞中很明显，这表明一氧化氮和活性氧在通气组织的发育中起关键作用。然而，抗氧化基因在通气组织发育过程中的作用尚不清楚，因此，我们检测了缺氧处理后不同时间点各种抗氧化剂（如超氧化物歧化酶1、交替氧化酶1A、抗坏血酸过氧化物酶和锰超氧化物歧化酶）的基因表达，发现这些基因的表达在2小时时升高，但在24小时时下调，此时通气组织的发育很明显。此外，我们发现生长在铵态氮营养条件下的植物通气组织发育延迟。综上所述，这篇简短通讯中提出的新见解突出了抗氧化基因表达在通气组织发育过程中的额外调控作用。
