National Research Center for Apple Engineering and Technology; Shandong Collaborative Innovation Center of Fruit and Vegetable Quality and Efficient Production; College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, 271018, Shandong, China.
Planta. 2024 Mar 7;259(4):86. doi: 10.1007/s00425-024-04355-9.
MdPRX34L enhanced resistance to Botryosphaeria dothidea by increasing salicylic acid (SA) and abscisic acid (ABA) content as well as the expression of related defense genes. The class III peroxidase (PRX) multigene family is involved in complex biological processes. However, the molecular mechanism of PRXs in the pathogen defense of plants against Botryosphaeria dothidea (B. dothidea) remains unclear. Here, we cloned the PRX gene MdPRX34L, which was identified as a positive regulator of the defense response to B. dothidea, from the apple cultivar 'Royal Gala.' Overexpression of MdPRX34L in apple calli decreased sensitivity to salicylic acid (SA) and abscisic acid（ABA). Subsequently, overexpression of MdPRX34L in apple calli increased resistance to B. dothidea infection. In addition, SA contents and the expression levels of genes related to SA synthesis and signaling in apple calli overexpressing MdPRX34L were higher than those in the control after inoculation, suggesting that MdPRX34L enhances resistance to B. dothidea via the SA pathway. Interestingly, infections in apple calli by B. dothidea caused an increase in endogenous levels of ABA followed by induction of ABA-related genes expression. These findings suggest a potential mechanism by which MdPRX34L enhances plant-pathogen defense against B. dothidea by regulating the SA and ABA pathways.
MdPRX34L 通过增加水杨酸（SA）和脱落酸（ABA）含量以及相关防御基因的表达来增强对 Botryosphaeria dothidea 的抗性。III 类过氧化物酶（PRX）多基因家族参与复杂的生物学过程。然而，PRX 在植物对 Botryosphaeria dothidea（B. dothidea）病原体防御中的分子机制尚不清楚。在这里，我们从苹果品种 'Royal Gala' 中克隆了 PRX 基因 MdPRX34L，该基因被鉴定为对 B. dothidea 防御反应的正调节剂。在苹果愈伤组织中过表达 MdPRX34L 会降低对水杨酸（SA）和脱落酸（ABA）的敏感性。随后，在苹果愈伤组织中过表达 MdPRX34L 会增加对 B. dothidea 感染的抗性。此外，在接种后，过表达 MdPRX34L 的苹果愈伤组织中 SA 含量和与 SA 合成和信号转导相关的基因表达水平均高于对照，表明 MdPRX34L 通过 SA 途径增强对 B. dothidea 的抗性。有趣的是，B. dothidea 在苹果愈伤组织中的感染会导致内源 ABA 水平升高，随后诱导 ABA 相关基因的表达。这些发现表明 MdPRX34L 通过调节 SA 和 ABA 途径增强植物-病原体防御 B. dothidea 的潜在机制。
