Preventive Effects of Fluoro-Substituted Benzothiadiazole Derivatives and Chitosan Oligosaccharide against the Rice Seedling Blight Induced by Fusarium oxysporum.

Bo Ma,Kefei Tan,Chuanzeng Liu,Ming Yuan,Zhijia Gai,Fuyang Zhao,Junhua Zhang,Junhe Wang,Jifang Hu

doi:10.3390/plants8120538

Abstract

Rice seedling blight, caused by Fusarium oxysporum, significantly affects global rice production levels. Fluoro-substituted benzothiadiazole derivatives (FBT) and chitosan oligosaccharide (COS) are elicitors that can enhance plant resistance to pathogen infection. However, there is a lack of information regarding FBT and COS used as elicitors in rice seedlings blight. Therefore, the aim of this study was to evaluate the effect of FBT and COS treatments on rice seedling blight and elucidate the molecular mechanisms of the two elicitors for inducing resistance using proteomic technique. Results indicated that FBT and COS significantly reduced the disease incidence and index, and relived the root growth inhibition caused by F. oxysporum (p < 0.05). Biochemical analyses demonstrated that these two elicitors effectively enhanced activities of defense enzymes. Moreover, the proteomic results of rice root tissues disclosed more differentially expressed proteins in diterpenoid biosynthesis pathway that were particularly stimulated by two elicitors compared to the other pathways studied, resulting in the accumulation of antimicrobial substance, momilactone. Findings of this study could provide sound theoretical basis for further applications of FBT and COS used as rice elicitors against seedling blight.

Highlights

Rice (Oryza sativa L.) is an important global cereal crops that provides a stable food supply for more than 5 billion people worldwide
Activity was
In response to numerous pathogen attacks, plants amass a formidable defense system by using a number of biotic and abiotic resources that serve as elicitors, a defense strategy largely known as induced resistance [36,37]

Summary

Introduction

Rice (Oryza sativa L.) is an important global cereal crops that provides a stable food supply for more than 5 billion people worldwide. Grain yield losses due to seedling blight infection ranges from 8 to 50% depending on severity of the disease, stage of the crop at which it was infected by the fungus, and overall environmental conditions [2,3,4]. Several species belonging to Fusarium, Rhizoctonia and Rhizopus groups have been isolated from infected roots to cause seedling blight [5,6,7]. Among these fungus, the Fusarium genus was regarded as the major pathogens of rice seedling blight in China [8,9]. As a wide-ranging pathogens, Fusarium oxysporum was usually selected to induce seedling blight by many researchers [10,11]

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