基于转录组测序的蝴蝶兰低温胁迫响应MYB转录因子挖掘OA北大核心CSTPCD

In order to explore the function of MYB transcription factor in the response of cold-resistant Phalaenopsis to low temperature stress,this research obtained a total of 31 MYB transcription factors with complete ORF from transcriptome library of Phalaenopsis cultivars under low temperature stress,and analyzed their structural domain,physicochemical properties,phylogenetic evolution,and expression characteristics.The results were as follows:there were 19 sequences belonging to R2R3-MYB,with W(T/-S/I)X2EDX2LX7GX3WX2(L/V/I)X3(A/T/S)(G/S)LXR(C/T/S)GKSCRLRWXNY of the amino acid arrangement pattern for R2 repeat,and(F/I/M/L)(S/T)X2EX3(I/V)(I/L/V)X(L/V)HX2(L/W)G(N/T)(R/K)-W(S/A)XIAX2LPGRTDNE(I/V)KNXW(N/R/H)(T/S/G)of the amino acid arrangement pattern for R3 repeat;there were 12 sequences belonging to 1R-MYB,with W(S/T)X(E/D)EHX2FLX(A/G)X4(G/D)-(R/K)G0-1(A/D)W or W(S/T)X(E/K)(Q/E)(N/D)KXFE(R/K)AL(A/V)X3(E/D)X(T/A)PXRW of the amino acid arrangement pattern for R repeat.All these 31 sequences had a Myb-DNA-binding domain.The average relative molecular weight and theoretical isoelectric point were 30 288.28 and 7.55 for 31 MYB proteins in Phalaenopsis,respectively;all of them were hydrophobic proteins.MYB transcription factor TRINITY_DN61754_c4_g1 was almost unchanged in Phalaenopsis cultivar Big Chili among the whole process,while the expression level was decreased in the early stage of cold treatment in Phalaenopsis cv.Fuller's Sunset.The expression level of RINITY_DN74288_c0_g1 was increased obviously at 48 h after cold treatment in Big Chili,however,the level was decreased remarkablely at 24 h after cold stress compared to normal temperature in Fuller's Sunset.Based on the phylogenetic analysis and functional prediction of MYB transcription factors between in Phalaenopsis equestris and Phalaenopsis cultivars,it is speculated that these two genes may play important roles in response to low temperature stress in Phalaenopsis.