Echinochloa crus-galli genome analysis provides insight into its adaptation and invasiveness as a weed
First author:Longbiao Guo; Affiliations: Zhejiang University(浙江大学): Hangzhou, China
Corresponding author:Longjiang Fan (樊龙江)
Barnyardgrass (Echinochloa crus-galli; 稗草) is a pernicious (有害的) weed (杂草) in agricultural fields (农业领域) worldwide. The molecular mechanisms underlying its success in the absence of human intervention (人为干涉) are presently unknown. Here we report a draft genome sequence of the hexaploid (六倍体的) species E. crus-galli, i.e., a 1.27 Gb assembly representing 90.7% of the predicted genome size. An extremely large repertoire of genes encoding cytochrome (细胞色素) P450 monooxygenases (单加氧酶) and glutathione S-transferases (谷胱甘肽硫转移酶) associated with detoxification (解毒) are found. Two gene clusters involved in the biosynthesis of an allelochemical (化感物质) 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA; 2,4-二羟基-7-甲氧基-(2H)-1,4-苯并噁嗪-3(4H)-酮) and a phytoalexin (植物抗毒素) momilactone A (稻内酯A) are found in the E. crus-galli genome, respectively. The allelochemical DIMBOA gene cluster is activated in response to co-cultivation (共栽培) with rice, while the phytoalexin momilactone A gene cluster specifically to infection by pathogenic Pyricularia oryzae (稻瘟病菌). Our results provide a new understanding of the molecular mechanisms underlying the extreme adaptation of the weed.