Page 173 - 《广西植物》2023年第12期
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12 期 林欣琪等: γ ̄氨基丁酸(GABA)种子引发缓解辣椒盐胁迫的效果及生理生化的变化 2 3 3 9
Abstract: Seed priming is proved to be an efficient way to improve crop salt toleranceꎬ which is a measure of pre ̄treating
seed with various agents while obtaining enhancement to crop performance at growing stage. Gamma amino butyric acid
(GABA) is a non ̄protein amino acid involved in various metabolic processesꎬ and partially protects plants from
environmental stress. Enhancing effects of GABA priming on germination characteristics and abiotic stress have been
established in several crops. Howeverꎬ the effect and mechanism of GABA seed priming on salt tolerance of pepper
(Capsicum annuum) are still unknown. In this studyꎬ a hybrid pepper variety of ‘Maoshu 360’ Chaotian pepper was used
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as materialꎬ the effects of seed priming with various concentrations of GABA (0ꎬ 1.0ꎬ 2.0ꎬ 4.0ꎬ 6.0ꎬ 8.0 μmolL ) on
plant biomassꎬ leaf osmotic regulating substanceꎬ leaf antioxidant capacityꎬ leaf photosynthesis systemꎬ potassium and
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sodium ion uptake and distribution between leaves and shoots of pepper plants under 100 mmolL NaCl stress applied at
4-6 leaf stage were investigated. The results were as follows: (1) From the point of plant growth under salt stressꎬ the best
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concentration of GABA for seed priming of pepper was 6.0 μmolL ꎬ which greatly boosted the biomass of pepper plants
under salt stress. (2) The mechanisms of GABA seed priming promoting salt tolerance of pepper were further analyzed. Seed
priming increased the leaf contents of soluble sugarꎬ soluble proteinꎬ chlorophyll and prolineꎬ decreased the leaf contents of
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O and malondialdehyde (MDA)ꎬ enhanced the leaf activities of antioxidant enzymesꎬ including super oxide dismutase
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(SOD)ꎬ peroxidase ( POD)ꎬ catalase ( CAT) and ascorbate peroxidase ( APX)ꎬ and raised several chlorophyll
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fluorescence metricsꎬ including F ′/ F ′ꎬ qP_Lssꎬ QY_Lssꎬ NPQ_Lss and Rfdꎬ reduced the K content and K / Na ratio in
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roots and stems. (3) For a comprehensive understanding of the mechanisms of GABA seed priming promoting salt tolerance
of pepperꎬ grey correlation analysis was carried out. Based on results of grey correlation analysisꎬ seed priming with GABA
significantly alleviated salt stress to pepper plants by boosting the activities of the antioxidant enzymes POD and CAT as well
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as increasing the levels of osmotic regulators. In conclusionꎬ seed priming with 6.0 μmolL GABA significantly increases
salt tolerance of pepper seedlingsꎬ probably by improving antioxidant and osmotic regulating capacities of pepper plants.
Key words: γ ̄aminobutyric acid ( GABA)ꎬ Capsicum annuum ( pepper)ꎬ seed primingꎬ salt toleranceꎬ grey
correlation analysis
近年来ꎬ全球已有 1.1×10 hm 陆地表面受到 激素平衡、激活抗氧化系统、调节渗透势以及排斥
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2
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盐渍化 的 影 响ꎬ 我 国 盐 渍 土 总 面 积 达 3. 69 × 10 有毒离子等( Neto et al.ꎬ 2005ꎻ Abdel Latef et al.ꎬ
hm ꎬ盐渍化已成为农业可持续生产的重要障碍 2019)ꎮ
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(杨劲松等ꎬ2022)ꎮ 土壤盐分作为一种非生物胁 种子引发是一种新兴的、提高植株生长发育
迫因子ꎬ主要通过降低种子萌发率、影响植株活 期逆境抗性的种子处理技术ꎬ其作用机制目前尚
力、细胞离子稳态和代谢途径来对作物产量产生 不清楚ꎬ可能是通过控制种子的有限活化或逆境
不利 影 响 ( Shabala et al.ꎬ 2016ꎻ Elbadri et al.ꎬ 驯化ꎬ改变基因的表达模式ꎬ使之处于耐受逆境的
2021)ꎮ 辣椒( Capsicum annuum) 是重要的茄果类 准备状态( 李洁等ꎬ2016)ꎮ 种子引发可激活应激
蔬菜ꎬ在我国的种植面积超过 2.1 × 10 hm ( 邹学 反应系统ꎬ使种子在暴露于未来的胁迫时ꎬ具有
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校等ꎬ2020)ꎮ 辣椒对盐度敏感或中等敏感ꎬ生长 “交叉耐受性”(Bhanuprakash & Yogeeshaꎬ 2016)ꎮ
发育过程中受到的盐胁迫会导致产量降低和果实 目前ꎬ种子引发作为一种实用、经济、低风险、无生
品质下降( 胡华冉等ꎬ2022)ꎮ 国内外学者对盐逆 物安全风险的栽培措施ꎬ不但能够改善逆境下种
境的作用机制进行了广泛研究ꎬ目前主要认为盐 子的萌发和出苗( Migahid et al.ꎬ 2019)ꎬ而且可通
分会 直 接 或 间 接 地 引 起 活 性 氧 ( reactive oxygen 过记忆效应提高植株生长发育期的逆境抗性ꎬ这
speciesꎬ ROS)的过量积累和氧化胁迫(Abdel Latef & 种记忆效应甚至可遗传(Margarete et al.ꎬ 2019)ꎮ
Heꎬ 2014)ꎬ造成离子毒性和营养失衡ꎬ限制水分 γ ̄氨基丁酸( γ ̄aminobutyric acidꎬGABA) 是一
吸收、降低光合效率ꎬ最终导致生长发育不良或植 种非蛋白四碳氨基酸ꎬ由谷氨酸脱羧或二胺氧化
株死亡( Cuartero et al.ꎬ 2006ꎻ Afzal et al.ꎬ 2008ꎻ 酶降解多胺产生的新型植物生长调节物质( Wang
Nouman et al.ꎬ 2014)ꎮ 植物可采用多种机制应对 et al.ꎬ 2014)ꎮ 植株在逆境胁迫时ꎬGABA 可在细
盐胁迫ꎬ如调节气孔、维持细胞膜的完整性、改变 胞中快速积累ꎬ通过提高抗氧化应激反应ꎬ调节碳