Jan Rahmatullah, Asif Saleem, Asaf Sajjad, Khan Zakirullah, Khan Waleed, Kim Kyung-Min
Department of Applied Biosciences, Graduate School, Kyungpook National University, Daegu, Republic of Korea.
Coastal Agriculture Research Institute, Kyungpook National University, Daegu, Republic of Korea.
Front Plant Sci. 2024 Jul 18;15:1419999. doi: 10.3389/fpls.2024.1419999. eCollection 2024.
The (Horváth) (Homoptera: Delphacidae) is a white-backed planthopper (WBPH) that causes "hopper burn" in rice, resulting in severe yield loss. Gamma-aminobutyric acid (GABA) is a well-known neurotransmitter that inhibits neurotransmission in insects by binding to specific receptors. In this study, we investigated the potential role of GABA in modulating rice resistance to WBPH and evaluated possible defense mechanisms. The experiment was conducted in green house in pots consist of four groups: control, GABA-treated, WBPH-infested, and WBPH-infested treated with GABA. Among the various tested concentration of GABA, 15 mM GABA was applied as a single treatment in water. The treatment was administered one week before WBPH infestation. The results revealed that 15 mM GABA treatment strongly increased WBPH resistance. A plate-based assay indicated that direct application of 15 mM GABA increased the mortality rate of WBPH and increased the damage recovery rate in rice plants. We found that GABA treatment increased the activation of antioxidant enzymes and reduced the reactive oxygen species content and malondialdehyde contents, and reduced the damage rate caused by WBPH. Interestingly, GABA-supplemented plants infested with WBPH exhibited increased phenylalanine ammonia-lyase and pathogenesis-related (PR) genes expression levels. GABA induced the accumulation of abscisic acid (ABA) and salicylic acid (SA) and enhanced the stomata closure and reduced leaf vessels to reduce water conductance during WBPH stress. Furthermore, we found that GABA application to the plant induced the expression of Jasmonic acid (JA) biosynthesis genes (, , , and ) and melatonin biosynthesis-related genes (, , , and ). Our study suggested that GABA increases resistance against WBPH infestation by regulating antioxidant defense system, TCA cycle regulation, phytohormonal signaling, and PR gene regulation.
褐飞虱（同翅目：飞虱科）是一种白背飞虱（WBPH），会导致水稻出现“虱烧”现象，从而造成严重的产量损失。γ-氨基丁酸（GABA）是一种著名的神经递质，它通过与特定受体结合来抑制昆虫的神经传递。在本研究中，我们调查了GABA在调节水稻对褐飞虱抗性中的潜在作用，并评估了可能的防御机制。实验在温室的花盆中进行，分为四组：对照组、GABA处理组、褐飞虱侵染组和用GABA处理的褐飞虱侵染组。在各种测试的GABA浓度中，15 mM GABA以单一处理方式施用于水中。该处理在褐飞虱侵染前一周进行。结果表明，15 mM GABA处理显著增强了水稻对褐飞虱的抗性。基于平板的试验表明，直接施用15 mM GABA可提高褐飞虱的死亡率，并提高水稻植株的损伤恢复率。我们发现，GABA处理可增加抗氧化酶的活性，降低活性氧含量和丙二醛含量，并降低褐飞虱造成的损伤率。有趣的是，用GABA处理的受褐飞虱侵染的植株中，苯丙氨酸解氨酶和病程相关（PR）基因的表达水平有所提高。GABA诱导脱落酸（ABA）和水杨酸（SA）的积累，增强气孔关闭并减少叶脉，以降低褐飞虱胁迫期间的水分传导。此外，我们发现对植株施用GABA可诱导茉莉酸（JA）生物合成基因（、、、和）和褪黑素生物合成相关基因（、、、和）的表达。我们的研究表明，GABA通过调节抗氧化防御系统、三羧酸循环调节、植物激素信号传导和PR基因调节来增强对褐飞虱侵染的抗性。
