香蕉束顶病毒(BBTV)侵染对寄主内源激素的影响

 本试验用ELISA方法测定了香蕉感染束顶病毒(BBTV)后植株体内的3种内源激素,赤霉素(GA₃)、玉米素类(iPAs)和脱落酸(ABA)的变化。结果表明,感株的GA₃水平在侵染过程中虽有微弱增加,但含量和增长速度显著低于健株对照;iPAs在接种BBTV第14天后明显下降,并维持较低水平;ABA在BBTV侵染后被大量诱导增加并不断积累,在接种后第35天测定含量最高,为对照的3.34倍。试验还同时检测了BBTV在侵染过程中的运转。用间接ELISA测定的接种叶和顶叶的BBTV含量显示:接种21天后BBTV在接种叶和顶叶中还大量增殖,呈系统性分布。但寄主的症状在接种35天后才逐渐在顶叶表现。以上结果表明:香蕉束顶病的症状表现似乎主要与病株中的内源激素的失调有关,而与BBTV在体内的运转并不直接相关

EFFECT OF BANANA BUNCHY TOP VIRUS (BBTV) ON ENDOGENOUS HORMONES OF BANANA PLANT

Three endogenous hormone contents of banana plants infected by BBTV, including gibberellic acid (GAs), isopentenyladenine group (iPAs) and abscisic acid (ABA), were detected by enzyme linked immunosorbent assay (ELISA) in this test. The results showed that the GAs contents of inoculated plants at different infecting periods were all lower than that of healthy plants, in spite of increasing slightly during infection. The iPAs contents of infected plants decreased significantly after 14th day of BBTV inoculation and kept in lower level during infection. ABA was greatly induced and accumulated in banana plants infected by BBTV. The ABA content of infected plants tested in 35th day of BBTV inoculation was highest and was 3.34 times of the control. The movement of BBTV in infected banana plants was determined in the same time in this test. The BBTV contents in inoculated leaves and in top leaves detected by indirect ELISA respectively indicated that BBTV particles replicated greatly both in inoculated leaves and top leaves after 21th day of inoculation. However, the symptom of infected banana plants appeared in top leaves after 35th day of inoculation. All these results indicated that the symptom of banana bunchy top disease may be closely related to the unbalance of endogenous hormones of infected plants, but indirectly related to the BBTV movement within plant.