Division of Plant-Microbe Interactions, Council of Scientific and Industrial Research-National Botanical Research Institute (CSIR-NBRI), Rana Pratap Marg, Lucknow, 226001, India.
Department of Botany, Dayanand Anglo-Vedic (PG) College (Affiliated to CSJM University, Kanpur), Civil Lines, Kanpur, 208001, U.P., India.
Microbiol Res. 2018 Oct;215:164-174. doi: 10.1016/j.micres.2018.07.008. Epub 2018 Jul 19.
During biotic stress, plants use several mechanisms to protect themselves that include the production of reactive oxygen species (ROS), induction of pathogenesis-related proteins and cell death. Some plant growth promoting rhizobacteria (PGPR) are known to act as bio-control agents that protect crops against pathogens. The biocontrol activity of PGPR Paenibacillus lentimorbus (B-30488) against Sclerotium rolfsii showed previously where several defense-related genes were upregulated with ROS induction in tomato. We further evaluate the other possibility, i.e. role of autophagy in enhancing defense in tomato using PGPR. Confocal microscopy revealed the presence of an acidotropic dye Mono Dansyl Cadaverine (MDC) stained autophagosomes in B-30488 treated healthy and infected plants. These autophagosomes almost disappeared in plants treated with an autophagy inhibitor chloroquine. The results were also confirmed by ultrastructural analysis of leaf tissues using transmission electron microscopy. Enhanced expression of autophagy-related genes was also monitored in B-30488 primed fungal infected tissues as compared to control by qRT-PCR. Results of ROS accumulation, fluorescence, confocal and transmission electron microscopy and gene expression analysis revealed induction of autophagy using B-30488 as a biocontrol agent suggesting a role in enhancing disease resistance in tomato. Overall, the present study indicated a role of B-30488 as a biocontrol in enhancing disease resistance in tomato and also assists a better understanding of fungal pathogenesis that is expected to be useful in developing new strategies for disease control.
在生物胁迫下，植物会利用多种机制来保护自身，包括产生活性氧（ROS）、诱导病程相关蛋白和细胞死亡。一些植物促生根际细菌（PGPR）被认为是生物防治剂，可以保护作物免受病原体侵害。先前已经证明，PGPR 类芽孢杆菌（B-30488）对核盘菌（Sclerotium rolfsii）具有生物防治活性，在番茄中诱导 ROS 产生的同时，上调了几种防御相关基因。我们进一步评估了使用 PGPR 增强番茄防御的另一种可能性，即自噬作用。共聚焦显微镜显示，在 B-30488 处理的健康和感染植物中存在酸性染料单丹磺酰尸胺（MDC）染色的自噬体。在使用自噬抑制剂氯喹处理的植物中，这些自噬体几乎消失了。超微结构分析也通过透射电子显微镜对叶片组织进行了证实。通过 qRT-PCR 监测到，与对照相比，B-30488 处理的真菌感染组织中自噬相关基因的表达增强。ROS 积累、荧光、共聚焦和透射电子显微镜以及基因表达分析的结果表明，B-30488 作为生物防治剂诱导自噬，这表明它在增强番茄抗病性方面的作用。总的来说，本研究表明 B-30488 作为生物防治剂在增强番茄抗病性方面发挥作用，同时也有助于更好地理解真菌发病机制，有望为开发新的疾病控制策略提供帮助。
