Genome-wide Identification And Expression Analysis Of Brnsltps Gene Family In Brassica Rapa

Non-specific lipid transfer proteins(nsLTPs) are small and basic proteins characterized by a conserved pattern of eight cysteines, forming four disulfide bridges. There are many different functions of nsLTPs have been reported in plants such as the adaptation to various environmental conditions, defense reactions against bacterial and fungal pathogens, sexual reproduction, and especially for mediating lipid transfer. Rape is important oil crops in China, and the main goals of rape breeding are the increasement of seed oil content and the improvement of fatty acid composition. Since one of the major roles of nsLTPs is regulation of lipid transfer, thus they may affect the rape seed oil content and fatty acid composition. However, no genome-wide analysis of the rape nsLTPs gene family has been performed so far. So our objective was to characterize the complete nsLTPs gene family in rape. In our study, a total of 77 putative BrnsLTPs genes were identified through a comprehensive in silico analysis of the whole genome of Brassica rapa. Based on the sequence similarities, these BrnsLTPs were grouped into ten types(I, II, III, IV, V, VI, VII, VIII, IX, and Y). The analysis of syntenic relationship demonstrated that whole genome duplication(WGD) was the primary means of expanding the members of BrnsLTPs family. The transcription profiles showed that the BrnsLTPs genes had different expression patterns in various organs or tissues. Some BrnsLTPs were only or mainly expressed in siliques, indicating they may have a relationship with the seed oil content and fatty acid composition. Furthermore, most of the BrnsLTPs genes showed the response to Pi. Taken together, the genome-wide identification, bioinformatic analysis and expression analysis of BrnsLTPs genes should facilitate the research of this gene family and provide new insight towards elucidating their biological functions in the oil content and fatty acid composition of seed.