Molecular Characterization, Evolutionary Analysis, and Expression Profiling of BOR Genes in Important Cereals.

Boron (B) is an essential micronutrient of plants. Plants grapple with a narrow range of B between its toxicity and deficiency. B homeostasis mechanism is required to rescue plants from such a quagmire. B transporters are specialized proteins involved in the homeostasis of B. In the present study, a total of 29 BOR genes were identified in five major cereals, including three BORs in each Brachypodium distachyon and Sorghum bicolor, four in Oryza sativa, six in Zea mays, and 13 in Triticum aestivum. Multiple sequence alignments, domain structure analyses, and phylogenetic analysis indicated the conserved nature of the BOR protein family. Duplication events and Ka/Ks analysis of TaBORs showed the role of segmental duplication events and purifying selection in the expansion of the BOR family in T. aestivum. Furthermore, in silico expression and co-expression analyses under biotic and abiotic stress conditions depicted their involvement in combating such conditions. Moreover, qRT-PCR of TaBORs in B treatment suggested the roles of BOR genes in B stress management. The present study hints at the conserved nature of BOR proteins and their different aspects. The study will lay down a way for several crop improvement programs.

Evolutionary Insights Based on SNP Haplotypes of Red Pericarp, Grain Size and Starch Synthase Genes in Wild and Cultivated Rice.

The origin and domestication of rice has been a subject of considerable debate in the post-genomic era. Rice varieties have been categorized based on isozyme and DNA markers into two broad cultivar groups, Indica and Japonica. Among other well-known cultivar groups Aus varieties are closer to Indica and Aromatic varieties including Basmati are closer to Japonica, while deep-water rice varieties share kinship to both Indica and Japonica cultivar groups. Here, we analyzed haplotype networks and phylogenetic relationships in a diverse set of genotypes including Indian Oryza nivara/Oryza rufipogon wild rice accessions and representative varieties of four rice cultivar groups based on pericarp color (Rc), grain size (GS3) and eight different starch synthase genes (GBSSI, SSSI, SSIIa, SSIIb, SSIIIa, SSIIIb, SSIVa, and SSIVb). Aus cultivars appear to have the most ancient origin as they shared the maximum number of haplotypes with the wild rice populations, while Indica, Japonica and Aromatic cultivar groups showed varying phylogenetic origins of these genes. Starch synthase genes showed higher variability in cultivated rice than wild rice populations, suggesting diversified selection during and after domestication. O. nivara/O. rufipogon wild rice accessions belonging to different sub-populations shared common haplotypes for all the 10 genes analyzed. Our results support polyphyletic origin of cultivated rice with a complex pattern of migration of domestication alleles from wild to different rice cultivar groups. The findings provide novel insights into evolutionary and domestication history of rice and will help utilization of wild rice germplasm for genetic improvement of rice cultivars.