Abstract Rapeseed is one of important oil crops in China. Better understanding of the regulation network of main agronomic traits of rapeseed could improve the yielding of rapeseed. In this study, we obtained an influrescence mutant that showed a fusion phenotype, similar with the Arabidopsis clavata-like phenotype, so we named the mutant as Bnclavata-like (Bnclv-like). Phenotype analysis illustrated that abnormal development of the inflorescence meristem (IM) led to the fused-inflorescence phenotype. At the stage of protein abundance, major regulators in metabolic processes, ROS metabolism, and cytoskeleton formation were seen to be altered in this mutant. These results not only revealed the relationship between biological processes and inflorescence meristem development, but also suggest bioengineering strategies for the improved breeding and production of Brassica napus.

Abstract Senescence, a highly programmed process, largely determines yield and quality of crops. However, knowledge about the onset and progression of leaf senescence in crop plants is still limited. Here, we report that salt-induced protein (salT), a new gene, may be involved in leaf senescence. Overexpressing salT could prolong the duration of leaves with higher concentrations of chlorophyll compared with the wild type. Moreover, overexpression of salT could delay the senescence of rice leaves though the inhibition of senescence associated genes (SAGs). Overall, the characterization of salT suggested that it is a new gene affecting the leaf senescence induced by natural and dark conditions.

Indica and japonica are two main subspecies of Asian cultivated rice (Oryza sativa L.) that differ clearly in morphological and agronomic traits, in physiological and biochemical characteristics and in their genomic structure. However, the proteins and genes responsible for these differences remain poorly characterized. In this study, proteomic tools, including two-dimensional electrophoresis and mass spectrometry, were used to globally identify proteins that differed between two sequenced rice varieties (93-11 and Nipponbare). In all, 47 proteins that differed significantly between 93-11 and Nipponbare were identified using mass spectrometry and database searches. Interestingly, seven proteins were expressed only in Nipponbare and one protein was expressed specifically in 93-11; these differences were confirmed by quantitative real-time PCR and proteomic analysis of other indica and japonica rice varieties. This is the first report to successfully demonstrate differences in the protein composition of indica and japonica rice varieties and to identify candidate proteins and genes for future investigation of their roles in the differentiation of indica and japonica rice.

Seeds are the most important plant storage organ and play a central role in the life cycle of plants. Since little is known about the protein composition of rice (Oryza sativa) seeds, in this work we used proteomic methods to obtain a reference map of rice seed proteins and identify important molecules. Overall, 480 reproducible protein spots were detected by two-dimensional electrophoresis on pH 4-7 gels and 302 proteins were identified by MALDI-TOF MS and database searches. Together, these proteins represented 252 gene products and were classified into 12 functional categories, most of which were involved in metabolic pathways. Database searches combined with hydropathy plots and gene ontology analysis showed that most rice seed proteins were hydrophilic and were related to binding, catalytic, cellular or metabolic processes. These results expand our knowledge of the rice proteome and improve our understanding of the cellular biology of rice seeds.

We surveyed the substitution patterns in the ent-kaurenoic acid oxidase (KAO) gene in 11 species of Oryzeae with an outgroup in the Ehrhartoidaea. The synonymous and non-synonymous substitution rates showed a high positive correlation with each other, but were negatively correlated with codon usage bias and GC content at third codon positions. The substitution rate was heterogenous among lineages. Likelihood-ratio tests showed that the non-synonymous/synonymous rate ratio changed significantly among lineages. Site-specific models provided no evidence for positive selection of particular amino acid sites in any codon of the KAO gene. This finding suggested that the significant rate heterogeneity among some lineages may have been caused by variability in the relaxation of the selective constraint among lineages or by neutral processes.