Weed biology andmanagement in the multi-omics era:Progress and perspectives

Weeds pose a significant threat to crop production,resulting in substantial yield reduction.In addition,they possess robust weedy traits that enable them to survive in extreme environments and evade human con-trol.In recent years,the application of multi-omics biotechnologies has helped to reveal the molecular mechanisms underlying these weedy traits.In this review,we systematically describe diverse applications of multi-omics platforms for characterizing key aspects of weed biology,including the origins of weed spe-cies,weed classification,and the underlying genetic and molecular bases of important weedy traits such as crop–weed interactions,adaptability to different environments,photoperiodicflowering responses,and herbicide resistance.In addition,we discuss limitations to the application of multi-omics techniques in weed science,particularly compared with their extensive use in model plants and crops.In this regard,we provide a forward-looking perspective on the future application of multi-omics technologies to weed science research.These powerful tools hold great promise for comprehensively and efficiently unraveling the intricate molecular genetic mechanisms that underlie weedy traits.The resulting advances will facilitate the development of sustainable and highly effective weed management strategies,promoting greener practices in agriculture.

Programmed sequential cutting endows Cas9 versatile base substitution capability in plants

Dear Editors,CRISPR/Cas9-mediated genome editing techniques have triggered a revolution in biology research(Jinek et al.,2012).Cas9 coupled with guide RNAs cuts DNA at precise positions,and the resulting double stranded breaks(DSB)were effectively repaired by non-homologous end joining(NHEJ)pathway in higher eukaryotic cells,including animals and plants.

Genomic insights into the origin, adaptive evolution, and herbicide resistance of Leptochloa chinensis, a devastating tetraploid weedy grass in rice fields

Chinese sprangletop (Leptochloa chinensis), belonging to the grass subfamily Chloridoideae, is one of the most notorious weeds in rice ecosystems. Here, we report a chromosome-scale reference genome assembly and a genomic variation map of the tetraploid L. chinensis. The L. chinensis genome is derived from two diploid progenitors that diverged ∼10.9 million years ago, and its two subgenomes display neither fractionation bias nor overall gene expression dominance. Comparative genomic analyses reveal substantial genome rearrangements in L. chinensis after its divergence from the common ancestor of Chloridoideae and, together with transcriptome profiling, demonstrate the important contribution of tetraploidization to the gene sources for the herbicide resistance of L. chinensis. Population genomic analyses of 89 accessions from China reveal that L. chinensis accessions collected from southern/southwestern provinces have substantially higher nucleotide diversity than those from the middle and lower reaches of the Yangtze River, suggesting that L. chinensis spread in China from the southern/southwestern provinces to the middle and lower reaches of the Yangtze River. During this spread, L. chinensis developed significantly increased herbicide resistance, accompanied by the selection of numerous genes involved in herbicide resistance. Taken together, our study generated valuable genomic resources for future fundamental research and agricultural management of L. chinensis, and provides significant new insights into the herbicide resistance as well as the origin and adaptive evolution of L. chinensis.