Mapping causal genes and genetic interactions for agronomic traits using a large F2 population in rice

Moving beyond the arabidopsis-centric view of G-protein signaling in plants

Heterotrimeric G-protein-mediated signaling is a key mechanism to transduce a multitude of endogenous and environmental signals in diverse organisms. The scope and expectations of plant G-protein research were set by pioneering work in metazoans. Given the similarity of the core constituents, G-protein-signaling mechanisms were presumed to be universally conserved. However, because of the enormous diversity of survival strategies and endless forms among eukaryotes, the signal, its interpretation, and responses vary even among different plant groups. Earlier G-protein research in arabidopsis (Arabidopsis thaliana) has emphasized its divergence from Metazoa. Here, we compare recent evidence from diverse plant lineages with the available arabidopsis G-protein model and discuss the conserved and novel protein components, signaling mechanisms, and response regulation.

A Pseudo-near isogenic F2 population strategy for rapid QTL cloning

Near isogenic F2 (NIF2) population frequently developed by conventional backcross has dramatically contributed to QTL identification in plants. Developing such a NIF2 population is time-consuming. Thus, it is urgent to rapidly produce a NIF2 population for QTL cloning. Here, we proposed a rapid QTL cloning strategy by generating a Pseudo-near isogenic F2 population (Pseudo-NIF2), which segregates at the target QTL but is fixed at other QTLs for the target trait. Nineteen QTLs for GL, GW, and TGW were detected in the F2 population from the cross between Zhenshan 97 and Egy316. To verify the efficiency of Pseudo-NIF2 in QTL quick cloning, the novel moderate QTL qGL10.1 which explained 9.1% and 5.6% of grain length variation in F2 and F2:3 populations was taken as an example. An F2 plant (F2-120), which segregated at qGL10.1 but fixed at other 8 QTLs for grain length, was screened to generate a Pseudo-NIF2 population by selfing cross. In the Pseudo-NIF2 population, the segregation ratio of plants with long grains to short grains fits 3:1, indicating that one gene controlled the variation of grain length. Based on the Pseudo-NIF2 and its progeny, qGL10.1 was fine mapped to a 19.3-kb region, where a gene OsMADS56 was verified as the candidate by functional polymorphism between parental alleles. Pseudo-NIF2 strategy is a rapid way for QTL cloning, which saves 3 to 4 cropping seasons compared to the conventional way. Applying the method for cloning QTL with moderate or major effects is promising.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11032-023-01408-x.