Li Yiliang, Su Xiaohua, Zhang Bingyu, Huang Qinjun, Zhang Xianghua, Huang Rongfeng
Institute of Forestry, Chinese Academy of Forestry and Key Laboratory for Cultivation and Silviculture of Forest Trees, State Forestry Administration, Beijing 100091, China.
Tree Physiol. 2009 Feb;29(2):273-9. doi: 10.1093/treephys/tpn025. Epub 2008 Dec 30.
The stress resistance of plants can be enhanced by regulating the expression of multiple downstream genes associated with stress resistance. We used the Agrobacterium method to transfer the tomato jasmonic ethylene responsive factors (JERFs) gene that encodes the ethylene response factor (ERF) like transcription factor to the genome of a hybrid poplar (Populus alba x Populus berolinensis). Eighteen resistant plants were obtained, of which 13 were identified by polymerase chain reaction (PCR), reverse transcriptase PCR and Southern blot analyses as having incorporated the JERFs gene and able to express it at the transcriptional level. Salinity tests were conducted in a greenhouse with 0, 100, 200 and 300 mM NaCl. In the absence of NaCl, the transgenic plants were significantly taller than the control plants, but no statistically significant differences in the concentrations of proline and chlorophyll were observed. With increasing salinity, the extent of damage was significantly less in transgenic plants than that in control plants, and the reductions in height, basal diameter and biomass were less in transgenic plants than those in control plants. At 200 and 300 mM NaCl concentrations, transgenic plants were 128.9% and 98.8% taller, respectively, and had 199.8% and 113.0% more dry biomass, respectively, than control plants. The saline-induced reduction in leaf water content and increase in root/crown ratio were less in transgenic plants than in control plants. Foliar proline concentration increased more in response to salt treatment in transgenic plants than in control plants. Foliar Na(+) concentration was higher in transgenic plants than in control plants. In the coastal area in Panjin of Liaoning where the total soil salt concentration is 0.3%, a salt tolerance trial of transgenic plants indicated that 3-year-old transgenic plants were 14.5% and 33.6% taller than the control plants at two field sites. The transgenic plants at the two field sites were growing vigorously, had dark green leaves and showed no symptoms of salt damage, implying that the JERFs gene enhanced their salt tolerance.
通过调控多个与抗逆相关的下游基因的表达，可以增强植物的抗逆性。我们采用农杆菌介导法，将编码类乙烯响应因子（ERF）转录因子的番茄茉莉酸乙烯响应因子（JERFs）基因转入杂种杨树（银白杨×毛白杨）基因组中。共获得18株抗性植株，其中13株经聚合酶链反应（PCR）、逆转录PCR和Southern杂交分析鉴定，已整合JERFs基因并能在转录水平表达。在温室中用0、100、200和300 mM NaCl进行盐胁迫试验。在无NaCl条件下，转基因植株显著高于对照植株，但脯氨酸和叶绿素含量无统计学显著差异。随着盐浓度升高，转基因植株的损伤程度显著低于对照植株，其株高、基径和生物量的降低幅度也小于对照植株。在200和300 mM NaCl浓度下，转基因植株的株高分别比对照植株高128.9%和98.8%，干生物量分别比对照植株多199.8%和113.0%。盐胁迫导致的转基因植株叶片含水量降低和根冠比增加幅度小于对照植株。转基因植株叶片脯氨酸浓度对盐处理的响应增加幅度大于对照植株。转基因植株叶片Na(+)浓度高于对照植株。在辽宁盘锦沿海土壤总盐浓度为0.3%的地区进行转基因植株耐盐性试验，结果表明，在两个田间试验点，3年生转基因植株比对照植株分别高14.5%和33.6%。两个田间试验点的转基因植株生长旺盛，叶片深绿，无盐害症状，表明JERFs基因增强了它们的耐盐性。
