旱作水稻西瓜间丛枝菌根菌丝桥诱导水稻磷转运蛋白的表达及对磷吸收的影响

采用中间隔网的土培根箱试验,对旱作水稻或/和西瓜接种丛枝菌根真菌(简称AM真菌)幼套球囊霉(Glomus etunicatum Becker&Gerdemann),研究了旱作水稻/西瓜间形成菌丝桥并诱导水稻磷酸盐转运蛋白OsPT11的表达和对磷吸收的影响。结果表明:(1)根箱两侧均未接种AM真菌时,旱作水稻和西瓜根系均不形成菌根,水稻根系的磷酸盐转运蛋白OsPT11也不表达。(2)西瓜侧接种AM真菌时,西瓜与水稻间形成的菌丝桥引起水稻菌根的形成,并诱导水稻根系磷酸盐转运蛋白OsPT11表达。(3)菌丝桥侵染和直接接种侵染对旱作水稻和西瓜形成丛枝菌根能达到相同的效果,旱作水稻和西瓜的菌根侵染率分别为80%以上和70%以上。(4)在旱作水稻/西瓜间作系统中,当接种AM真菌时,水稻和西瓜根际有效磷含量显著高于对照处理,水稻地上部全磷含量降低,而西瓜地上部全磷含量升高。

Expression of rice phosphate transporter induced by mycorrhizal hyphal links between aerobic rice and watermelon and its effects on phosphorus absorption

A rhizobox experiment was carried out, using boxes each separated into two compartments in the middle with nylon net and planted with aerobic rice and/or watermelon, both inoculated with Glomus etunicatum of arbuscular mycorrhizal fungi (abbreviated as AM fungus), to investigate formation of arbuscular mycorrhizal hyphal links between the roots of the two plants, and their effects on expression of OsPT11, phosphate transporter in rice, and uptake of phosphorus. Results showed that when neither aerobic rice nor watermelon was inoculated with AM fungus, no mycorrhiza colonized and no expression of OsPT11 was observed either in rice roots; (2) When the watermelon compartment was incubated, the hyphal links formed between aerobic rice and watermelon induced colonization of mycorrhiza on rice and expression of OsPT11 in the root system of rice; (3) Inoculation either directly or indirectly through hyphal links displayed the same effect on colonization of mycorrhiza in aerobic rice and watermelon, making the colonization rate over 80% and over 70%, respectively; and (4) In the aerobic rice/watermelon interplanting system, inoculation significantly increased availability of phosphorus in the rhizosphere of both aerobic rice and watermelon as compared to control, and the content of total phosphorus decreased in the shoots of rice, but increased in the shoots of watermelon.