AM真菌提高烟草钾含量机制的初步研究

One Possible Mechanism of Glomous mosseae Infection Increasing Tobacco Potassium Uptake

以烟草和AM真菌菌株摩西球囊霉(Glomous mosseae,G.m)为材料,研究了不同外界K+浓度条件下AM真菌对烟草生长、K+含量以及根中K+-通道基因NtKT1、NtKT2和转运体基因NtHAK1、NtHA1相对表达量的影响。结果表明,在低钾和常钾条件下,接种G.m均可提高烟草的株高,增加根系长度,提高烟草根部和叶片中的K+含量,在低钾条件下接种G.m使烟草根部和叶片的K+含量分别提高了50.5%和24.5%。在常钾条件下,接种G.m 50 d后烟草根系中NtKT1和NtKT2的相对表达量显著提高;而低钾条件下,钾转运体基因NtHAK和NtHA1的相对表达量显著升高。由此推测,AM真菌能够调控烟草根中K+-通道基因和钾转运体基因的表达进而促进其对K+的吸收。

Using arbuscular mycorrhizal （AM） fungi Glomous mosseae （G.m） and Nicotiana tabacum as materials, the effects of AM fungi on the growth and potassium uptake of tobacco were studied, the transcripts of potassium channel gene NtKT1 and NtKT2 as well as potassium transporter gene NtHAK and NtHA1 were also detected aimed to reveal the possible mechanism of AM fungi infection prompting potassium uptake in tobacco. The results showed that G.m infection increased plant height, root length as well as potassium contents in roots and leaves of tobacco. Under low exogenous potassium condition, the potassium contents in roots and leaves of tobacco inoculated with G.m increased 50.5% and 24.5% respectively compared with the non-inoculated plants. Under normal exogenous potassium conditions, the relative expression of potassium channel gene NtKT1 and NtKT2 increased significantly after inoculation with G.m for 50 d, but under low exogenous potassium condition, transcripts of potassium transporter gene NtHAK and NtHA1 increased significantly. These resulteds indicated that AM fungi could regulate expression of potassium ion channel gene NtKT1 and NtKT2 as well as potassium transporter gene NtHAK and NtHA1 to promote tobacco potassium uptake under different exogenous potassium condition.