Oligopeptide is one family of short peptides containing several amino acids, it can be used as the required carbon nitrogen resource during organ material and energy metabolism, as well as signals mediating multiple biological functions. Its main function so far is to rapid transport the extracellular oligopeptides into cells. Now most study only focus on bacterial and animal, the relevant study on plan remains less.

The groups leaded by Profs. YANG Yongping HU Xiangyang from KIB, combined Prof. HUANG Jinglin in East Carolina University and Dr. CAO Jun from Jiangsu University, carried out the study on the gene family of OPTs in poplar and grape. Phylogenetic analyses show OPT genes consist of two classes that can be further subdivided into 11 groups. Gene structures are considerably conserved among the groups. The distribution of OPT genes was found to be non-random across chromosomes. A high proportion of the genes are preferentially clustered, indicating that tandem duplications may have contributed significantly to the expansion of the OPT gene family. Expression patterns based on our analyses of microarray data suggest that many OPT genes may be important in stress response and functional development of plants. Further analyses of functional divergence and adaptive evolution show that, while purifying selection may have been the main force driving the evolution of the OPTs, some of critical sites responsible for the functional divergence may have been under positive selection.

 This work was supported by 100 Talents Program of CAS (to X.H.) and grants from the National Science Foundation of China (No. 30871704 and No. 30971452 to X.H., No. 30900871 to L.Y.). http://www.biomedcentral.com/1471-2164/12/465

Chromosomal locations of the Populus OPT genes.

The schematic diagram shows the17 OPT genes mapped to 8 chromosomes. (image by HU Xiangyang)