| Drought, high salinity and cold were the serious abiotic stress factors that adversely influenced the growth and yield of plant. For a long time, people always try to cultivate crop to adapt to variety abiotic stresses. Transcription factor is a potential canidate to improve the ability of comprehensive resistance. NF-Y is a kind of nuclear transcription factor playing roles in multiple biological process, such as regulation of flowering time and stress resistant. Meanwhile, transcription factor was under its promoter control. The sequences of plant gene promoters include plenty of vital elements and regulate it downstream genes expression in transcription level. In this paper, we cloned the Brassica napus NF-YA and NF-YC gene family and isolated their promoters, the expression pattern of BnNF-YA and BnNF-YCwere examined. The main findings of this study are as follows:According to the known full sequence of Arabidopsis NF-Y, BnNF-YA/C were acquired based on EST blast analysis in Brassica database. Our study have cloned 14 BnNF-YAs and 5 BnNF-YCs from Brassica napus’ Nanyan 1st’. Through the gDNA and cDNA alignments, all the BnNF-YA family members owned 3-5 introns and most of BnNF-YC family members have none intron. We identified two pairs of alternative splice variants, BnNF-YA4/5 and BnNF-YA13/14. Brassica napus NF-Y subunits are close to Arabidopsis NF-Y instead of monocots, such as rice.The gene expression of 19 BnNF-Y members in whole growth period in different tissues were determined by real-time quantitive analysis. The result showed that different BnNF-Y gene had different expression pattern. Some of them had tissue specificity. However, similarities in expression pattern between NF-YA and NF-YC subfamily members exist. This implied that part of subunits may form NF-YA/B/C complex and function together.Expression profiles of 12 BnNF-YAs and 5 BnNF-YCs were further tested under stress treatments. Transcript level of BnNF-YAs and BnNF-YCs under 150mM NaCl and 15% (w/v) PEG stress were examined in 0,1 and 3h, respectively. The stress-responsive BnNF-Y members were further tested under 100μM ABA for 0,1,3,6 and 24h. Our findings indicated that all BnNF-YA subunits and 3 BnNF-YC subunits are involve in stress resistant and some of them may be through ABA pathway.Based on PCR to amplify the promoters of all BnNF-YA subunits and 3 BnNF-YC subunits, BnNF-Y promoters contain important stress cis-acting elements via PLACE and plantCARE analysis. Our research will provide base to study the signal regulatory pathway of BnNF-Ys.BnNF-YA9, BnNF-YA12, BnNF-YA13, BnNF-YCl, BnNF-YC2 and BnNF-YC5 transgenic over-expression vectors were constructed and transformed to Agrobacterium tumefaciens. Using foral dip method,transgenetic wild-type Arabidopsis were obtained. |
