盐胁迫对氢氧化细菌WMQ7浸种小麦萌发和生长的影响

Effect of Salt Stress on the Germination and Growth of Wheat Seeds Soaked with Hydrogen-oxidizing Bacteria WMQ7

从紫花苜蓿根际土壤分离得到的一株含有ACC脱氨酶以及铁载体的氢氧化细菌WMQ7,通过皿内试验,考查其在不同盐浓度下对小麦‘陕优225’的促生效应。结果表明,低盐胁迫(0.4%NaCl)下,用氢氧化细菌WMQ7菌悬液浸种的小麦发芽粒数、发芽率、发芽势、发芽指数、胚芽、胚根长有明显的增高;同时脯氨酸积累速度与对照组相比显著减缓,对照组脯氨酸含量于胁迫第11天时已达1 383μg.mL-1,高出接菌组3.8倍;丙二醛含量与对照组相比减少了69.28%,过氧化物酶活性显著升高,高出对照组44.44%。而高盐胁迫下(0.8%NaCl),与对照组相比,接菌组对小麦萌发指标有一定影响,丙二醛含量变化不显著,但脯氨酸含量及过氧化物酶活性变化显著。研究表明,氢氧化细菌WMQ7浸种小麦处理对低盐胁迫的伤害有一定的缓解作用,但在高盐胁迫下却无明显效果。

A strain of hydrogen-oxidizing bacteria WMQ7 containing both ACC-deaminase and siderophore was isolated from alfalfa rhizosphere soil.The growth promoting effect of WMQ7 was evaluated under stress of different salt concentrations on wheat ＇Shaanyou 225＇.It showed that,under low salt stress（0.4% NaCl）,after being soaked with WMQ7 suspension,the germination numbers,germination rate,germination energy,germination index,embryo and radical length of the seeds increased significantly.Proline accumulation rate was significantly slowed compared with the control group.Proline content in the control group reached 1 383 μg·mL-1 after 11 days,which was 3.8 times higher than the inoculated group.MDA content decreased 69.28% compared with the control group and peroxidase activity increased 44.44% higher than the control group.While on high salt stress（0.8% NaCl）,the indexes changed insignificantly between control and inoculated groups.The results showed that hydrogen-oxidizing bacteria WMQ7 could mitigate low salt stress.