Sumayo Marilyn S, Son Jin-Soo, Ghim Sa-Youl
School of Life Sciences, BK21 Plus Kyungpook National University Creative BioResearch Group and Research Institute for Dokdo and Ulleung-do Island, Kyungpook National University, 80 Daehakru, Bukgu, Daegu 41566, Korea.
Funct Plant Biol. 2018 Oct;45(11):1119-1127. doi: 10.1071/FP17332.
Phenylacetic acid (PAA) was evaluated for its capability to promote plant growth and induce systemic resistance in tobacco (Nicotianum tabacum L cv. Xanthi) against the bacterial soft rot pathogen Pectobacterium carotovorum subsp. carotovorum (PCC). Exogenous application of PAA influenced root formation, the activities of defence-related enzymes and the expression of defence and growth-related genes. Increased formation of lateral roots can be observed in tobacco treated with higher PAA concentrations. The highest elicitation of induced systemic resistance (ISR) was found in plants treated with 0.5mM PAA, where the phytotoxic effect was minimal. The activities of the defence enzymes phenylalanine ammonia-lyase (PAL), peroxidase (POD) and polyphnenoloxidase (PPO) were modulated upon treatment with different PAA concentrations. Reverse transcription-PCR analyses showed that 0.5mM PAA modulated the expression of the growth-related genes NtEXP2 and NtEXP6, and the defence-related genes Coi1, NPR1, PR-1a and PR-1b. These results showed that different concentrations of PAA can elicit different responses and effects on tobacco growth and resistance. This study presents the important role of PAA not only on plant growth but also for plant immunity against phytopathogens.
研究评估了苯乙酸（PAA）促进烟草（Nicotianum tabacum L cv. Xanthi）生长以及诱导其对细菌性软腐病原菌胡萝卜软腐果胶杆菌胡萝卜亚种（PCC）产生系统抗性的能力。外源施加PAA影响根系形成、防御相关酶的活性以及防御和生长相关基因的表达。在较高PAA浓度处理的烟草中可观察到侧根形成增加。在用0.5mM PAA处理的植株中发现诱导系统抗性（ISR）的激发效果最佳，此时植物毒性效应最小。用不同浓度的PAA处理后，防御酶苯丙氨酸解氨酶（PAL）、过氧化物酶（POD）和多酚氧化酶（PPO）的活性受到调节。逆转录PCR分析表明，0.5mM PAA调节了生长相关基因NtEXP2和NtEXP6以及防御相关基因Coi1、NPR1、PR-1a和PR-1b的表达。这些结果表明，不同浓度的PAA可引发对烟草生长和抗性的不同反应及影响。本研究揭示了PAA不仅在植物生长方面，而且在植物对植物病原菌的免疫方面都具有重要作用。
