During wheat storage, the corn weevil (Sitopilus zeamais) is one of the most destructive pests that affect wheat yield and quality. Traditional methods to control maize weevils included fumigants (e.g., phosphine, methyl bromide, and medicinal plants) and insecticides (e.g., organophosphate fenitrothion, pyrethroid, and deltamethrin). Compared to harmful insecticides and fumigants, improving the inherent defense ability of wheat is a safer and more effective way to prevent corn weevil invasion. Therefore, understanding the defense mechanisms of wheat against corn weevil and effectively utilizing the defense-related genes and metabolites are necessary to enhance wheat resistance to maize weevils.

Recently, a researched paper entitled “Combined analysis of metabolome and transcriptome of wheat kernels reveals constitutive defense mechanism against maize weevils” was published online in Frontiers in Plant Science by wheat breeding team of Institute of Cereal and Oil Crops. This study obtained the resistant variety RIL-116 and sensitive variety RIL-72 of wheat to corn weevil through screening for two consecutive growth seasons. The combined analysis of metabolome and transcriptome of RIL-116 and RIL-72 wheat kernels revealed differentially accumulated metabolites were mainly enriched in flavonoids biosynthesis-related pathway, followed by glyoxylate and dicarboxylate metabolism, and benzoxazinoid biosynthesis. The flavonoid content of resistant cultivar RIL-116 was significantly higher than that of sensitive cultivar RIL-72. In addition, the expression of structural genes(FLS, F3’5’H,CHS) and transcription factors (MYC2, NAC78) related to flavonoids biosynthesis were up-regulated to varying degrees in RIL-116 than RIL-72. Taken together, these results indicated that the biosynthesis of flavonoids contributes the most to wheat defense against maize weevils. This study not only provides insights into the constitutive defense mechanism of wheat kernels against maize weevils, but may also play an important role in the breeding of resistant varieties.

Dr. LV Liangjie is the first author and Dr. GUO Xiaorui is the co-first author of the paper. Researcher LI Hui and CHEN Xiyong are co-corresponding authors of the paper.

Address of publication:
https://doi.org/10.3389/fpls.2023.1147145

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