College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China; Key Laboratory of Protected Horticultural Engineering in Northwest, Ministry of Agriculture, Yangling, Shaanxi, 712100, China; Shaanxi Protected Agriculture Research Centre, Yangling, Shaanxi, 712100, China.
College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China.
Plant Physiol Biochem. 2022 Oct 15;189:83-93. doi: 10.1016/j.plaphy.2022.08.013. Epub 2022 Aug 29.
5-Aminolevulinic acid (ALA), an antioxidant existing in plants, has been widely reported to participate in the process of coping with cold stress of plants. In this study, exogenous ALA promoted the growth of tomato plants and alleviated the appearance of purple tomato leaves under low-temperature stress. At the same time, exogenous ALA improved antioxidant enzyme activities, SlSOD gene expression, Fv/Fm, and proline contents and reduced HO contents, SlRBOH gene expression, relative electrical conductivity, and malondialdehyde contents to alleviate the damage caused by low temperature to tomato seedlings. Compared with low-temperature stress, spraying exogenous ALA before low-temperature stress could restore the indicators of photochemical quenching, actual photochemical efficiency, electron transport rate, and nonphotochemical quenching to normal. Exogenous ALA could increase the total contents of the xanthophyll cycle pool, the positive de-epoxidation rate of the xanthophyll cycle and improved the expression levels of key genes in the xanthophyll cycle under low-temperature stress. In addition, we found that exogenous ALA significantly enhanced the absorption of mineral nutrients, promoted the transfer and distribution of mineral nutrients to the leaves, and improved the expression levels of mineral nutrient absorption-related genes, which were all conducive to the improved adaptation of tomato seedlings under low-temperature stress. In summary, the application of exogenous ALA can increase tomato seedlings' tolerance to low-temperature stress by improving the xanthophyll cycle and the ability of the absorption of mineral nutrients in tomato seedlings.
5-氨基乙酰丙酸（ALA）是一种存在于植物中的抗氧化剂，已被广泛报道参与植物应对冷胁迫的过程。在本研究中，外源 ALA 促进了番茄植株的生长，并减轻了低温胁迫下紫叶番茄的出现。同时，外源 ALA 提高了抗氧化酶活性、SlSOD 基因表达、Fv/Fm 和脯氨酸含量，降低了 HO 含量、SlRBOH 基因表达、相对电导率和丙二醛含量，从而减轻了低温对番茄幼苗的伤害。与低温胁迫相比，在低温胁迫前喷洒外源 ALA 可以将光化学猝灭、实际光化学效率、电子传递率和非光化学猝灭的指标恢复正常。外源 ALA 可以增加叶黄素循环池的总含量、叶黄素循环的正向去氧化率，并提高低温胁迫下叶黄素循环关键基因的表达水平。此外，我们发现外源 ALA 显著增强了矿质养分的吸收，促进了矿质养分向叶片的转移和分配，并提高了矿质养分吸收相关基因的表达水平，这都有利于提高番茄幼苗在低温胁迫下的适应能力。综上所述，外源 ALA 的应用可以通过提高叶黄素循环和番茄幼苗吸收矿质养分的能力来增加番茄幼苗对低温胁迫的耐受性。
