| bZIPs is a large family of transcription factors in plants which play crucial roles in the regulation of plant growth, development and environmental stresses adaptation, but only a part of the family members have been studied so far and the molecular mechanism of the transcriptional regulation by bZIPs remain poorly understood. Pepper is an agriculturally important vegetable crop and also a diseases susceptible solanaceae. Considering that bZIPs play important roles in regulation of plant growth and stresses resistance, expression and function analysis of the individual members of the bZIPs family is helpful to dissect the molecular mechanism of plant growth, development and stresses adaptation. In this paper, expression of CabZIP1, a novel member of bZIP family in pepper was analyzed by real time PCR and its functional identification was carried out by overexpression in tobacco and VIGS in pepper, the main results are as followings:1. By real time PCR analysis of the expression of CabZIP1 against different stresses as well as exogenous phytohormones application, it was found that the expression of CabZIP1 was reduced by exogenous application of SA, and was enhanced by Cold, H2O2, NaCl treatment. The expression of CabZIP1 rose significantly against mechanical wounding within 6 h and decreased thereafter.2. Overexpression vectors of CabZIP1 was construced and transformed into tobacco by agrobacterium-mediated method. 45 T0 independent regenerated plantswere acquired and subjected to PCR detection to get ride of the false transgenic plants and the transgenic plants and their corresponding T1 lines were acquired.By using the transgenic T1 tobacco lines, the effect of CabZIP1 oversexpressionon resistance against biotic and abiotic stresses was studied. The results indicatd that, the overexpression of CabZIP1 increased the resistance to NaCl treatment as well as exogenous SA application. The overexpression of CabZIP1 increased the susceptivity of tobacco to Pseudomonas solanacearum infection. No different-ce in response to cold and hot treatments was detected between the overxpressi-on lines and the control. These results suggested that CabZIP1 could act as apo- sitive regulator to salt stress resistance and a negetive regulator to disease resist-ance. The experiment of real time PCR indicated that the overexpression of CabZIP1 enhanced the expression of 201 and PR3, decreased the expression of 203,515,H1N1and PR1. and expression of PR2 was not affected by the overex-pression of CabZIP1.3. VIGS(Virus induced gene silence)studies showed that gene silence of CabZIP1 improved resistance to Pseudomonas solanacearum infection, but conferred sensitive to salt stress in pepper plants. |
