Sivamani E, Bahieldin1 A, Wraith JM, Al-Niemi T, Dyer WE, Ho TD, Qu R
Ain Shams University, Cairo, Egypt
Plant Sci. 2000 Jun 12;155(1):1-9. doi: 10.1016/s0168-9452(99)00247-2.
The ABA-responsive barley gene HVA1, a member of group 3 late embryogenesis abundant (LEA) protein genes, was introduced into spring wheat (Triticum aestivum L.) cv. Hi-Line using the biolistic bombardment method. High levels of expression of the HVA1 gene, regulated by the maize ubi1 promoter, were observed in leaves and roots of independent transgenic wheat plants and were inherited by offspring generations. T(3) progenies of four selected transgenic wheat lines were tested under greenhouse conditions for tolerance of soil water deficit. Potted plants were grown under moderate water deficit and well-watered conditions, respectively. Two homozygous and one heterozygous transgenic lines expressing the HVA1 gene had significantly (P<0.01) higher water use efficiency values, 0.66-0.68 g kg(-1), as compared to 0.57 and 0.53 g kg(-1), respectively, for the non-expressing transgenic and non-transgenic controls under moderate water deficit conditions. The two homozygous transgenic plant lines also had significantly greater total dry mass, root fresh and dry weights, and shoot dry weight compared to the two controls under soil water deficit conditions. Results of this study indicate that growth characteristics were improved in transgenic wheat plants constitutively expressing the barley HVA1 gene in response to soil water deficit.
ABA 应答型大麦基因 HVA1 是第 3 组晚期胚胎丰富（LEA）蛋白基因的成员，通过生物弹道轰击法被导入春小麦（Triticum aestivum L.）品种 Hi-Line 中。在独立的转基因小麦植株的叶片和根中观察到由玉米 ubi1 启动子调控的 HVA1 基因的高水平表达，并且这种表达可遗传给后代。在温室条件下对四个选定转基因小麦品系的 T(3) 后代进行土壤水分亏缺耐受性测试。盆栽植物分别在中度水分亏缺和充分浇水条件下生长。与中度水分亏缺条件下不表达的转基因和非转基因对照分别为 0.57 和 0.53 g kg(-1) 相比，两个纯合和一个杂合表达 HVA1 基因的转基因品系的水分利用效率值显著（P<0.01）更高，为 0.66 - 0.68 g kg(-1)。在土壤水分亏缺条件下，两个纯合转基因植株系与两个对照相比，总干重、根鲜重和干重以及地上部干重也显著更大。本研究结果表明，组成型表达大麦 HVA1 基因的转基因小麦植株在响应土壤水分亏缺时生长特性得到改善。
