Influences Of Low PH On The Arbuscule Formation And Function Of Tomato Hairy Root

Acid red soil is an important soil resource in south China,occupies more than a third of the total land area.But its low soil pH,the lack of nutrients inhibit crops in the yield,quality and so on.AM fungi(arbuscular mycorrhizal fungi,AMF)is a kind of ancient microorganism and plant obligate symbiosis,can survive in many types of soil.It is widely distributed in nature.AM fungi can effectively improve the resistance of plants to low p H which promote the growth of plants.At the same time AM fungi plays an important role in the improvement of acid soil.In this paper,the root capsule was used as the research object.The tomato hairy roots were used as host,and the two chamber Petri dishes(root chamber RC an d Mycelial cell HC)were used as the device,set up four processing RC/HC: 6.5/6.5,RC/HC: 6.5/4.5,RC/HC: 4.5/6.5,RC/HC: 4.5/4.5.The response of the plant roots and AMF to low p H(4.5)compared with normal pH(6.5),and the comparison of root and exogenous hyphae with low p H(4.5)compared with normal pH(6.5)were investigated in the symbiotic state.The specific results were obtained by measureeing the mycorrhizal infection rate,the alkaline phosphatase activity of mycorrhizal and exogenous hyphae,the accumulation of polyphosphate(polyP)in the exogenou s hyphae,and the gene expression of LePT phosphotransferase.The results are as follows:1.Under the condition of AM fungi and tomato hairy root double culture system,compared with the normal p H6.5,the content of P root,the mycorrhizal infection rate(total root infection rate,infection rate of shoots,relative rate of shoot infection rate),alkaline phosphatase activity of mycorrhiza,gene expression of LePt phosphotransferase was significantly decreased in p H4.5,This indicates that the root sys-tem can respond to the low p H,and this response is strong.2.Under the condition of AM fungi and tomato hairy root double culture system,compared with the normal pH6.5,the alkaline phosphatase activity and the accumulation of polyphosphate(polyP)in the mycelium of AM fungi were significantly decreased at low p H 4.5,indicating that the hyphae in the mycelial cells can respond to the low p H,and this response is strong.3.The correlation between root and AM fungi hyphae was studied by ariance partitioning correlation analysis.The results showed that in the same treatment,the response of root to low pH was stronger than that of AM fungi hyphae.