AM真菌对盐胁迫下番茄幼苗生理特征及AVP1表达的影响

采用温室盆栽试验研究不同NaCl浓度（0、50 和85 mmol/L）持续胁迫接种摩西球囊霉和地表球囊霉 2种AM真菌对加工番茄耐盐性的影响。结果显示:（1）在0 mmol/L NaCl处理条件下,2种菌的番茄菌根化苗的根系活力、叶片中可溶性糖、可溶性蛋白、根系脯氨酸含量以及超氧化物歧化酶和过氧化物酶活性均高于非菌根植株,且丙二醛含量低于非菌根植株,但差异不显著。（2）在50、85 mmol/L NaCl浓度胁迫下,接种2种菌根真菌可显著提高番茄植株根系活力,促进叶片中可溶性糖、可溶性蛋白及根系脯氨酸含量的积累,显著提高叶片中与抗逆相关的超氧化物歧化酶和过氧化物酶的活性,减少丙二醛在根系中的积累;随着NaCl浓度的增加,效果更为明显。（3）RT-PCR分析显示,AM真菌和盐胁迫共同调控H⁺转运无机焦磷酸酶H⁺- PPase的表达,随NaCl浓度的增加,AVP1基因表达量下降,但菌根化番茄植株的AVP1基因表达量显著高于非菌根植株。研究表明,接种AM真菌后,菌根化植株可通过显著促进幼苗体内渗透调节物质积累和抗氧化酶活性的提高,有效降低体内膜脂过氧化水平,同时过量表达AVP1基因增加了番茄植株中离子向液泡膜的转运,从而缓解盐胁迫对植株的伤害,增强番茄幼苗对盐胁迫的耐性。

Effect of AM Fungi on Processing Tomato Seedlings Physiological Characteristics and AVP1 Gene Expression under Salt Stress

The effects of 2 species AM fungi (G.mosseae,G.versiforme) on salt tolerance of processing tomato were studied in pot culture under different NaCl concentrations (0,50 and 85 mmol/L).The results showed that:(1)Under 0 mmol/L NaCl conditions,compared with non-mycorrhizal plant,mycorrhizal plant can enhance root activity,promote the accumulation of soluble sugar,soluble protein in leaves and proline content in roots,promote SOD and POD activities in leaves and reduce accumulation of MDA content,but no significant difference.(2)Under 50 mmol/L and 85 mmol/L NaCl stress,compared with non-mycorrhizal plant,mycorrhizal plant significantly enhanced root activity,promoted the accumulation of soluble sugar,soluble protein in leaves and proline content in roots,promoted SOD and POD activities in leaves and reduced accumulation of MDA content.(3)Expression of H⁺-PPase (AVP1) gene was studied by qRT-PCR and it was regulated by AMF and salt stress jointly.With the increasing of the concentration of salt,the AVP1 gene expression decreased.AVP1 gene expression of mycorrhizal plant is higher than that in non-mycorrhizal plant distinctly.We concluded that inoculation G.mosseae and G.versiforme to processing tomato can enhance the seedlings osmotic adjustment mechanism of salt tolerance,raise the activities of antioxidant and AVP1 gene expression.So the damage of salt stress on the plant would be alleviated and the adapt ablity of processing tomato seedlings to salt environment would be improved.