Yang Yuxian, Xia Jiaxin, Fang Xiang, Jia Haoran, Wang Xicheng, Lin Yiling, Liu Siyu, Ge Mengqing, Pu Yunfeng, Fang Jinggui, Shangguan Lingfei
College of Horticulture, Nanjing Agricultural University, Nanjing, Jiangsu, China.
Fruit Crop Variety Improvement and Seedling Propagation Engineering Research Center of Jiangsu Province, Nanjing, Jiangsu, China.
Front Plant Sci. 2023 Mar 15;14:1129114. doi: 10.3389/fpls.2023.1129114. eCollection 2023.
Drought is a common and serious abiotic stress in viticulture, and it is urgent to select effective measures to alleviate it. The new plant growth regulator 5-aminolevulinic acid ALA has been utilized to alleviate abiotic stresses in agriculture in recent years, which provided a novel idea to mitigate drought stress in viticulture. The leaves of 'Shine Muscat' grapevine ( L.) seedlings were treated with drought (Dro), drought plus 5-aminolevulinic acid (ALA, 50 mg/L) (Dro_ALA) and normal watering (Control) to clarify the regulatory network used by ALA to alleviate drought stress in grapevine. Physiological indicators showed that ALA could effectively reduce the accumulation of malondialdehyde (MDA) and increase the activities of peroxidase (POD) and superoxide dismutase (SOD) in grapevine leaves under drought stress. At the end of treatment (day 16), the MDA content in Dro_ALA was reduced by 27.63% compared with that in Dro, while the activities of POD and SOD reached 2.97- and 5.09-fold of those in Dro, respectively. Furthermore, ALA reduces abscisic acid by upregulating , thus, relieving the closure of stomata under drought. The chlorophyll metabolic pathway and photosynthetic system are the major pathways affected by ALA to alleviate drought. Changes in the genes of chlorophyll synthesis, including , , , and ; genes related to degradation, such as , , and ; the gene that is related to Rubisco; and the genes and related to photorespiration form the basis of these pathways. In addition, the antioxidant system and osmotic regulation play important roles that enable ALA to maintain cell homeostasis under drought. The reduction of glutathione, ascorbic acid and betaine after the application of ALA confirmed the alleviation of drought. In summary, this study revealed the mechanism of effects of drought stress on grapevine, and the alleviating effect of ALA, which provides a new concept to alleviate drought stress in grapevine and other plants.
干旱是葡萄栽培中常见且严重的非生物胁迫，因此迫切需要选择有效的缓解措施。新型植物生长调节剂5-氨基乙酰丙酸（ALA）近年来已被用于缓解农业中的非生物胁迫，这为减轻葡萄栽培中的干旱胁迫提供了新思路。对‘阳光玫瑰’葡萄（L.）幼苗的叶片进行干旱（Dro）、干旱加5-氨基乙酰丙酸（ALA，50 mg/L）（Dro_ALA）和正常浇水（对照）处理，以阐明ALA用于缓解葡萄干旱胁迫的调控网络。生理指标表明，ALA能有效降低干旱胁迫下葡萄叶片中丙二醛（MDA）的积累，并提高过氧化物酶（POD）和超氧化物歧化酶（SOD）的活性。处理结束时（第16天），Dro_ALA中的MDA含量比Dro降低了27.63%，而POD和SOD的活性分别达到Dro中的2.97倍和5.09倍。此外，ALA通过上调 降低脱落酸，从而缓解干旱条件下气孔的关闭。叶绿素代谢途径和光合系统是ALA缓解干旱影响的主要途径。叶绿素合成相关基因的变化，包括 、 、 和 ；与降解相关的基因，如 、 、 和 ；与核酮糖-1,5-二磷酸羧化酶/加氧酶（Rubisco）相关的 基因；以及与光呼吸相关的 基因和 基因构成了这些途径的基础。此外，抗氧化系统和渗透调节发挥着重要作用，使ALA能够在干旱条件下维持细胞内稳态。施用ALA后谷胱甘肽、抗坏血酸和甜菜碱的减少证实了干旱胁迫得到缓解。综上所述，本研究揭示了干旱胁迫对葡萄的影响机制以及ALA的缓解作用，为缓解葡萄及其他植物的干旱胁迫提供了新的思路。
