Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing, Jiangsu, China.
Jiangxi Academy of Forestry, Nanchang, Jiangxi, China.
PLoS One. 2020 Jul 9;15(7):e0235795. doi: 10.1371/journal.pone.0235795. eCollection 2020.
To investigate the growth, physiological changes and mechanism of drought resistance of Camellia oleifera GWu-2 under drought stress conditions, changes in the main growth and physiological indices of GWu-2 under different water gradients were studied. Factor analysis was used to study the differences between indicators under different water gradients, and correlation analysis was implemented to analyze the relationship between different factors. We observed that the growth state, enzyme secretion, stomatal morphology and leaf osmotic adjustment substances were significantly affected by drought stress. In particular, increases in leaf abscisic acid (ABA), indole acetic acid (IAA) and methyl jasmonate (MeJA) contents under drought stress were negatively correlated with the stomatal opening degree, and the ratio of ZR/GA3 was significantly correlated with the growth and physiological indicators of GWu-2, indicating that different hormones respond differently to drought stress and have different functions in the growth regulation and drought resistance of GWu-2. We concluded that the drought resistance mechanism of GWu-2 was controlled by maintaining root growth to obtain the necessary water, increasing the contents of osmotic substances of leaves to maintain water holding capacity, reducing the transpiration of water by increasing leaf ABA, IAA and MeJA content to close stomata and reducing the damage caused by drought by increasing the activity of superoxide dismutase (SOD).
为了研究油茶 GWu-2 在干旱胁迫条件下的生长、生理变化和抗旱机制，研究了不同水分梯度下 GWu-2 的主要生长和生理指标的变化。利用因子分析研究了不同水分梯度下指标的差异，并进行了相关分析，以分析不同因子之间的关系。我们观察到，干旱胁迫显著影响了油茶的生长状态、酶分泌、气孔形态和叶片渗透调节物质。特别是干旱胁迫下叶片脱落酸（ABA）、吲哚乙酸（IAA）和茉莉酸甲酯（MeJA）含量的增加与气孔开度呈负相关，而 ZR/GA3 的比值与 GWu-2 的生长和生理指标显著相关，表明不同激素对干旱胁迫的响应不同，在 GWu-2 的生长调控和抗旱性中具有不同的功能。我们得出结论，GWu-2 的抗旱机制是通过维持根系生长以获取必要的水分、增加叶片渗透物质含量以保持持水能力、通过增加叶片 ABA、IAA 和 MeJA 含量来减少水分蒸腾以关闭气孔、以及通过增加超氧化物歧化酶（SOD）的活性来减少干旱造成的损害来控制的。
