拟南芥VHA-c1基因对非生物胁迫的响应

The Responses of VHA-c1 Gene in Arabidopsis thaliana to Abiotic Stresses

为初步探讨V-ATPasec亚基VHA-c1基因在植物生长发育及信号转导中的作用,通过农杆菌介导,将设计的dsDNA片段整合到拟南芥基因组上,筛选获得了能够特异沉默VHA-c1基因的转基因株系c1-1,并对其进行NaCl、ABA和6%葡萄糖胁迫处理。结果表明:在NaCl处理后,沉默株系c1-1的主根伸长量和种子萌发率都有明显的降低,且在浓度为50,100mmol/LNaCl胁迫处理下,转基因株系c1-1的主根伸长量被显著抑制。在特定浓度的ABA和6%葡萄糖处理后,转基因株系c1-1的主根伸长量和种子萌发率也都有一定程度的抑制。然而,在4,8μmol/LABA处理后,野生株系的主根伸长量被显著抑制,与转基因株系c1-1的主根伸长量被抑制效果相比达到了显著水平。沉默VHA-c1基因后,降低了拟南芥对NaCl的耐受性,影响了其生长发育,然而对ABA和葡糖糖的抑制作用却表现为很不敏感,这可能是因为H+-ATPase在盐胁迫信号通路和ABA信号通路中起着不同的调控功能。

The vacuolar type H+-ATPase(VHA)is a multi-subunit endomembrane proton pump and plays a important role in plant adaptation and resistance to abiotic stresses.In order to explore the function of VHA subunit c gene(VHA-c1)in plant growth and signal transduction,the designed double strand DNA fragment was integrated into the genome of Arabidopsis thaliana by Agrobacterium mediation,and then a transgenic line c1-1 was screened to specifically silence the coding gene of VHA-c1 subunit.The results showed that the relative root length and the germination rate of seeds in c1-1 line decreased compared with the wild strain under the stress of NaCl.Especially,under the stress of 50,100 mmol/L NaCl,the relative root length of c1-1 line was suppressed sharply.Under the stress of ABA or glucose,the relative root length of c1-1 line and wild strain was suppressed.However,the relative root length of wild strain decreased more obviously than c1-1 line at 4,8μmol/L ABA treatment.It suggested that the silenced VHA-c1 gene significantly reduced the tolerance of Arabidopsis to NaCl,and was insensitive to ABA and glucose stresses.This might be due to the different regulatory functions of H+-ATPase in salt stress and ABA signaling pathways.