Zhu Kaijie, Feng Yimei, Huang Yufeng, Zhang Dongmei, Ateeq Muhammad, Zheng Xiongjie, Al-Babili Salim, Li Guohuai, Liu Junwei
National Key Lab for Germplasm Innovation and Utilization of Horticultural Crops, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, Hubei Province 430070, PR China.
Center for Desert Agriculture, Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia.
Tree Physiol. 2023 Nov 13;43(11):1933-1949. doi: 10.1093/treephys/tpad093.
The β-cyclocitric acid (β-CCA) is a bioactive apocarotenoid previously shown to improve drought tolerance in annual plants. However, the underlying molecular mechanism of this process remains largely elusive. Moreover, the question about the activity of β-CCA in perennial fruit crops is still open. Here, we found that treatment of β-CCA enhances drought tolerance in peach seedlings. The application of β-CCA significantly increased the relative water content and root activity and reduced the electrolyte leakage of peach seedlings under drought stress. Moreover, treatment with β-CCA under drought stress increased chlorophyll fluorescence, indicating a positive effect on photosynthesis, while also enhancing superoxide dismutase and peroxidase activity and reducing reactive oxygen species (ROS) levels. Consistent with these alterations, transcriptome analysis revealed an up-regulation of photosynthesis and antioxidant-related genes upon the application of β-CCA under drought stress. We also detected an induction in genes related to detoxification, environmental adaptation, primary metabolism, phytohormone, phenylpropanoid and the biosynthesis of cutin, suberine and wax, which might contribute to the induction of drought resistance. Altogether, our study reveals that β-CCA positively modulates peach drought tolerance, which is mainly mediated by enhancing photosynthesis and reducing ROS, indicating the potential of utilizing β-CCA for drought control in peach and perhaps other fruit crops.
β-环柠檬酸（β-CCA）是一种生物活性类胡萝卜素氧化产物，此前已证明其能提高一年生植物的耐旱性。然而，这一过程的潜在分子机制仍 largely 难以捉摸。此外，β-CCA 在多年生果树作物中的活性问题仍然悬而未决。在此，我们发现用β-CCA 处理可增强桃树苗的耐旱性。在干旱胁迫下，施用β-CCA 显著提高了桃树苗的相对含水量和根系活力，并降低了电解质渗漏。此外，在干旱胁迫下用β-CCA 处理可增加叶绿素荧光，表明对光合作用有积极影响，同时还增强了超氧化物歧化酶和过氧化物酶活性，并降低了活性氧（ROS）水平。与这些变化一致，转录组分析显示在干旱胁迫下施用β-CCA 后，光合作用和抗氧化相关基因上调。我们还检测到与解毒、环境适应、初级代谢、植物激素、苯丙烷类以及角质、栓质和蜡质生物合成相关的基因的诱导，这可能有助于诱导抗旱性。总之，我们的研究表明β-CCA 能正向调节桃树的耐旱性，这主要是通过增强光合作用和减少 ROS 来介导的，表明利用β-CCA 控制桃树及可能其他果树作物干旱的潜力。
