Overexpression of OsPGIP1 Enhances Rice Resistance to Sheath Blight

Abstract

Rice sheath blight (SB), caused by necrotrophic pathogen Rhizoctonia solani, is one of the most destructive rice diseases, and no major resistance genes are available. Polygalacturonase-inhibiting proteins (PGIP) are extracellular leucine-rich repeat proteins and play important roles in plant defense against different pathogenic fungi by counteracting secreted fungal polygalacturonases (PG). However, the role of PGIP in conferring resistance to rice SB remains to be thoroughly investigated. Here, we showed that OsPGIP1 is capable of inhibiting PG derived from R. solani. Our real-time reverse-transcription polymerase chain reaction results indicated that resistant rice ‘YSBR1’ and ‘Jasmine 85’ express significantly higher levels of OsPGIP1 than susceptible ‘Lemont’. Our results also show that OsPGIP1 is most highly expressed at the late tillering stage in the sheath of YSBR1, coinciding with the critical stage of SB development in field. More importantly, the OsPGIP1 level is highly elevated by inoculation with R. solani in resistant cultivars but not in susceptible Lemont. Overexpression of OsPGIP1 significantly increased rice resistance to SB and inhibited tissue degradation caused by R. solani-secreted PG. Furthermore, OsPGIP1 overexpression did not affect rice agronomic traits or yield components. Together, our results not only demonstrate the important role of OsPGIP1 in combatting the rice SB disease but also provide a new avenue to the improvement of rice SB resistance by manipulating an endogenous gene.

A Comprehensive Gene Expression Profile of Pectin Degradation Enzymes Reveals the Molecular Events during Cell Wall Degradation and Pathogenesis of Rice Sheath Blight Pathogen Rhizoctonia solani AG1-IA

“…More than 121 million raw reads and 113 million clean reads were obtained from RNA sequencing of R. solani infected tissue of TN1, BPT5204, Tetep, and Pankaj. These reads were mapped to the rice genome and the filtered reads were mapped to the R. solani genome [43,44] and transcriptome [41]. More than 3.0 million reads of Tetep, 2.0 million reads of Pankaj, and 1.0 million reads of BPT5204 could be mapped to R. solani genome.…”

Amino acid substitutions in a polygalacturonase inhibiting protein (OsPGIP2) increases sheath blight resistance in rice

“…In addition to their function in PG inhibition, PGIPs promote the accumulation of oligogalacturonide (OGs) elicitors, which induce host defense responses (Federici et al 2006; Ferrari et al 2013). Transgenic plants partially silenced for PGIP genes expression showed enhanced susceptibility to fungal infection, whereas transgenic plants overexpressing PGIP genes displayed more resistance to fungi (Ferrari et al 2006; Chen et al 2016; Liu et al 2016). These studies demonstrate the important roles of PGIPs in the modulation of plant defense to fungal ingress.…”

Antimicrobial Resistance with Special Emphasis on Pathogens in Agriculture

“…The activity of defense can be boosted by targeting molecules such as reactive oxygen species, pathogenesis-related genes involved in defense regulation, signaling, and associated processes activating acquired resistance. Such measures were profited to a great extent in enhancing resistance to diseases such as citrus greening and pathogens such as Rhizoctonia solani and Magnaporthe oryzae that utilizes the plant's own natural immune system without the introduction of new or novel metabolic pathways [85,86].…”