Alfaro-Quezada Juan Felipe, Martínez Juan Pablo, Molinett Sebastian, Valenzuela Miryam, Montenegro Ivan, Ramírez Ingrid, Dorta Fernando, Ávila-Valdés Andrea, Gharbi Emna, Zhou Mingxi, Dailly Hélène, Quinet Muriel, Lutts Stanley, Seeger Michael
Laboratorio de Fisiología y Biología Molecular Vegetal, Instituto de Investigaciones Agropecuarias (INIA), Centro Regional La Cruz, Chorrillos 86, La Cruz, Chile.
Laboratorio de Microbiología Molecular y Biotecnología Ambiental, Departamento de Química, Universidad Técnica Federico Santa María, Avenida España 1680, Valparaíso, Chile.
J Exp Bot. 2023 Apr 27;74(9):2891-2911. doi: 10.1093/jxb/erad040.
Climate change has intensified the infection of tomato plants by pathogens such as Pseudomonas syringae pv. tomato (Pst). Rootstocks may increase plant tolerance to leaf phytopathogens. The aim of this study was to evaluate the effects of the tolerant Poncho Negro (R) tomato rootstock on physiological defence and the role of hydrogen sulfide (H2S) in susceptible Limachino (L) tomato plant responses to Pst attack. Ungrafted (L), self-grafted (L/L), and grafted (L/R) plants were infected with Pst. Rootstock increased the concentration of antioxidant compounds including ascorbate in the scion. Tolerant rootstock induced an increase of H2S in the scion, which correlated with enhanced expression of the SlAPX2 gene. A high accumulation of salicylic acid was observed in Pst-inoculated grafted L/L and L/R plants, but this was higher in L/R plants. The increase of H2S during Pst infection was associated with a reduction of ethylene in L/R plants. Our study indicates that the Poncho Negro rootstock reduced the symptoms of bacterial speck disease in the Limachino tomato plants, conferring tolerance to Pst infection. This study provides new knowledge about the impact of rootstock in the defence of tomato plants against leaf pathogens that could be used in sustainable management of tomato cultivation.
气候变化加剧了番茄植株被丁香假单胞菌番茄致病变种（Pst）等病原体的感染。砧木可能会提高植株对叶部植物病原体的耐受性。本研究的目的是评估耐性砧木“庞乔·内格罗（R）”番茄对生理防御的影响，以及硫化氢（H₂S）在感病“利马奇诺（L）”番茄植株对Pst攻击的反应中的作用。未嫁接（L）、自嫁接（L/L）和嫁接（L/R）的植株均接种了Pst。砧木提高了接穗中抗氧化化合物（包括抗坏血酸）的浓度。耐性砧木诱导接穗中H₂S增加，这与SlAPX2基因表达增强相关。在接种Pst的嫁接L/L和L/R植株中观察到水杨酸大量积累，但在L/R植株中积累量更高。Pst感染期间H₂S的增加与L/R植株中乙烯的减少有关。我们的研究表明，“庞乔·内格罗”砧木减轻了“利马奇诺”番茄植株上细菌性斑点病的症状，赋予了对Pst感染的耐受性。本研究提供了关于砧木在番茄植株抵御叶部病原体方面影响的新知识，可用于番茄种植的可持续管理。
