Size matters:G protein signaling is crucial for grain size control in rice

Rice is an important food crop and is consumed by nearly half of the world’s population.Rice grain size is a key yield trait and also affects the quality of grain appearance.Several pathways that control grain size have been identified in rice,such as heterotrimeric guanine nucleotide-binding protein(G protein)signaling,mitogen-activated protein kinase signaling,the ubiquitinproteasome pathway,phytohormone perception and homeostasis,and some transcriptional regulators(Li et al.,2019).