Breeding Base for State Key Laboratory of Land Degradation and Ecological Restoration of North-western China, Ningxia University, Yinchuan, China.
Key Lab for Restoration and Reconstruction of Degraded Ecosystem in North-western China of Ministry of Education, School of Ecology and Environment, Ningxia University, Yinchuan, China.
Microsc Res Tech. 2022 Nov;85(11):3707-3715. doi: 10.1002/jemt.24222. Epub 2022 Aug 19.
Previous research has reported that hypoxic conditions and ethylene treatments greatly trigger programmed cell death (PCD) occurrence and induce the formation of aerenchyma to adapt stress environment in Helianthus annuus stem. Caspase 3-like protease (CLP) as regulatory signals, also be involved in the process of PCD to adapt the low oxygen environment. However, the relationships between ethylene and CLP have seldom been reported. Herein, To understand the regulatory role of ethylene and CLP signaling molecules in aerenchyma formation, we investigated the effects of exogenous ethephon (ET), ethylene perception inhibitor 1-methylcyclopropene (1-MCP), and the treatment of 1-MCP + ET on morphological, physiological characteristics and aerenchyma formation in H. annuus stem. The results showed that lysigenous aerenchyma formation in H. annuus stem is induced by ET, and immunohistochemistry assay indicate CLP activity is raised at the formation stage of aerenchyma formation, and decreased at the expanding phase of aerenchyma formation. Western blotting illustrate the expression of CLP is also increased within 8 h after ethylene signaling inducing aerenchyma formation, and the activities of CLP are higher in ET treated seedlings than the control and 1-MCP treated seedlings. The same phenomenon was also observed by caspase-3 activity assay. These results revealed there is a causal and interdependent relationship between ET and CLP signaling during the process of aerenchyma formation, which regulating PCD initiation in H. annuus stem.
先前的研究报道称，低氧条件和乙烯处理会极大地触发程序性细胞死亡（PCD）的发生，并诱导 Helianthus annuus 茎中形成通气组织以适应胁迫环境。半胱氨酸蛋白酶 3 样蛋白酶（CLP）作为调节信号，也参与了 PCD 过程以适应低氧环境。然而，乙烯和 CLP 之间的关系很少有报道。在此，为了了解乙烯和 CLP 信号分子在通气组织形成中的调节作用，我们研究了外源乙烯利（ET）、乙烯感受抑制剂 1-甲基环丙烯（1-MCP）以及 1-MCP+ET 处理对向日葵茎形态、生理特性和通气组织形成的影响。结果表明，ET 诱导向日葵茎中的内生通气组织形成，免疫组织化学分析表明 CLP 活性在通气组织形成的形成阶段升高，在通气组织形成的扩展阶段降低。Western blot 分析表明，在乙烯信号诱导通气组织形成的 8 小时内，CLP 的表达也增加，并且 ET 处理的幼苗中的 CLP 活性高于对照和 1-MCP 处理的幼苗。caspase-3 活性测定也观察到了相同的现象。这些结果表明，在通气组织形成过程中，ET 和 CLP 信号之间存在因果和相互依存的关系，调节向日葵茎中 PCD 的起始。
