Comparative Genomic Analysis of Boron Transport Gene Family in Arabidopsis and Five Crops

Nutrient boron(B)is important for crop development.The absorption and transport of B ions are regulated by the B transport(BOR)gene family.Although some members of the BOR gene family have been heavily researched,to the best of our knowledge,no comprehensive research on the structural,evolutionary and functional relationships among crops has been reported.In this study,comparative genomic research of the BOR gene family was performed in five crops,40 BOR genes were identified,and analyses of phylogenetics,structure,conserved motifs,and transmembrane topology were performed.These genes had highly similar physicochemical properties,structure and motif distribution.Specific elements in the C-terminus and functional differences were also found among the genes.In addition,microsynteny and evolutionary analysis suggested that large-scale replication events and purifying selection played essential roles during the OsBOR gene evolutionary process in rice.Moreover,expression pattern of OsBORs were also analyzed.Our research provides comprehensive and detailed information on BOR genes in five crops and establishes a foundation for further functional exploration of these genes in B metabolic pathways.

Research Progress on Fertility of Two-line Male Sterile Rice Lines

Great achievements have been made in the exploration of male sterile resources, gene mapping and cloning and molecular mechanism revealing, as well as in breeding and application of two-line rice in China. This paper briefly reviewed the discovery, types and cloning of sterile genes in rice and molecular breeding of two-line rice, and summarized the research progress of critical sterility inducing temperature, so as to provide new ideas for the research and breeding of two-line hybrid rice.

An epi-allele of SMS causes Sanming dominant genic male sterility in rice

Male sterility is an important trait in rice for hybrid rice(Oryza sativa)breeding.However,the factors involved in dominant male sterility are largely unknown.Here,we identified a gene from Sanming dominant genic male sterile rice,named Sanming dominant male sterility(SMS),and reported that an epi-allele of this locus contributes to male sterility.Segregation analysis attributed dominant male sterility to a single locus,SMS,which we characterized using a male-sterile near isogenic line(NIL)of rice cultivar 93-11.The SMS locus was heterozygous in the male-sterile 93-11 NIL,containing an epi-allele identical to that in 93-11,and an epi-allele identical to that in rice cultivar Nipponbare,which we refer to as SMS9 and SMSN,respectively.SMS9is silent and hyper-methylated,whereas SMSNis expressed and hypo-methylated in the 93-11 NIL.Overexpressing SMSNled to male sterility.Mutations in SMS rescued the male sterility of the 93-11 NIL.Interestingly,we observed the duplication of SMSN in Nipponbare,but did not observe the duplication of SMS9in 93-11.Together,these findings suggest that the reduced methylation and enhanced expression of the SMSNepi-allele in the 93-11 NIL is responsible for its role in conferring dominant male sterility.