GL6.1 integrates grain length regulation and disease resistance via OsWRKY53-mediated signaling in rice

Grain size is a crucial factor influencing both rice yield and appearance quality. In this study, we identified GL6.1 as a gene associated with rice grain size by map-based cloning. The GL6.1 encodes a protein with CC-NB-LRR domain, a structural motif related to rice disease resistance. Genetic transformation experiments and the construction of gene pyramiding lines indicate that GL6.1 functions as a negative regulatory factor for rice grain length. By the analysis of SSSLs with diverse donor parents, a total of 11 single nucleotide polymorphisms (SNPs) are identified that are closely associated with the phenotype variations. A yeast one-hybrid library screening revealed that GL6.1 interacts with OsWRKY53, a transcription factor associated with rice disease resistance. Furthermore, RNA-seq assay also revealed the involvement of pathways associated with disease resistance, hinting at a multifaceted role for GL6.1 in both yield and stress tolerance traits in rice. These results indicate that the cloning and in-depth studies of GL6.1 would provide valuable insights into the interplay among high yield, superior quality and stress tolerance, which are critical goals for rice breeding.