AtSOS基因在紫花苜蓿中的表达及其耐盐性研究  

The expression of the salt tolerance gene AtSOS in Medicago

作　　者：麻冬梅[1] 秦楚[2] MA Dong- mei;QIN Chu(Breeding Base of State Key Laboratory lot Preventing Land Degradation and Ecological Restoration,Ningxia University Yinchuan 750021,China;College of Life Science,Ningxia University,Yinchuan 750021,China)

机构地区：[1]宁夏大学西北土地退化与生态恢复国家重点实验室培育基地,宁夏银川750021 [2]宁夏大学生命科学学院,宁夏银川750021

出　　处：《草业学报》2018年第6期81-91,共11页Acta Prataculturae Sinica

基　　金：宁夏自然科学基金项目(NZ15002)资助

摘　　要：本研究采用基因工程技术改良紫花苜蓿耐盐性,通过种植转基因耐盐紫花苜蓿达到改良土壤的目的。以紫花苜蓿子叶节为外植体,通过农杆菌介导法将来源于拟南芥的AtSOS1-AtSOS2-AtSOS3多基因表达载体导入阿尔冈金紫花苜蓿中,经PCR检测、抗除草剂筛选和RT-PCR鉴定,获得了能稳定表达的转基因株系。以转基因的紫花苜蓿和野生型紫花苜蓿为材料进行盐处理,每个处理重复3次,测定其生理生化指标、株高、Na+和K+含量、细胞膜透性、叶绿素含量。结果显示,在不同盐浓度处理下,所有植株的株高均有所增长,但在100和200mmol·L-1的NaCl处理下,转基因植株的长势显著高于野生型植株;随着处理时间的增加,所有植株的叶绿素含量均呈先上升后下降的趋势,且野生型植株叶绿素含量均低于转基因植株;在100和200mmol·L-1的NaCl处理下,转基因植株的细胞膜透性、超氧化物歧化酶活性和脯氨酸含量的增加量均小于野生型植株,而过氧化物酶、过氧化氢酶活性和可溶性糖含量的增加量均大于野生型;各植株中丙二醛含量均下降,且野生型植株下降的更为明显;盐处理后,转基因植株根系中Na+的积累比野生型植株少,而K+的吸收多于野生型植株。转AtSOS基因的紫花苜蓿通过发挥AtSOS途径的作用,促进了植物体将细胞内的Na+外排,从而减轻盐胁迫对植物体的伤害,提高了转基因植株的耐盐性。In this study,alfalfa was genetically engineered to improve its salt tolerance.The SOS1-SOS2-SOS3 genes fromArabidopsis thaliana were incorporated into Algonquin using tumefaciens-mediate transformation technology.Transgenic plants were identified by PCR,herbicide resistance screening and RT-PCR.The salt resistance of the transgenic plants was evaluated by exposing them to different concentration（100,200 and 300 mmol·L-1）of NaCl for 6 days and comparing them to unmodified plants.Physiological and biochemical indexes,plant height,Na＋and K＋content,cell membrane permeability and chlorophyll content were measured.The results showed that under different salt treatments,the height of all plants increased but transgenic plant height was significantly higher than that of unmodified plants at 100 and 200 mmol·L-1 NaCl.After salt exposure the chlorophyll content of all plants initially increased before declining but the chlorophyll content of unmodified plants was lower than that of transgenic plants.Under 100 and 200 mmol·L-1 NaCl treatments,membrane permeability,superoxide dismutase activity and proline content of transgenic plants were lower than that of unmodified plants.However,peroxidase activity,catalase activity and soluble sugar were higher than that of unmodified plants.Malondialdehyde content declined in all plants but the decline was greater in unmodified plants.The accumulation of Na＋in roots of transgenic plants was less than in unmodified plants,while K＋content was more than that of unmodified plants.Transgenic plants displayed increased Na＋efflux,reducing cellular ion toxicity,alleviating the damage from salt stress.

关 键 词：紫花苜蓿 AtSOS基因 遗传转化 耐盐性 

分 类 号：S541.9[农业科学—作物学]