玉米与大豆间作对玉米叶片衰老的影响

Effects of maize/soybean intercropping on maize leaf senescence

采用玉米/大豆2∶2间作和玉米净作的小区试验,检测与衰老相关酶在不同生育期的活性,并利用RT-PCR技术,检测不同生育期玉米衰老相关基因的表达情况。结果表明,与净作种植的玉米相比,间作种植的玉米能够维持较高的超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性,有效增加叶绿素、可溶性糖和可溶性蛋白含量,降低丙二醛(MDA)含量,有效延缓植物衰老。通过分析比较玉米/大豆间作种植与玉米净作种植模式下玉米衰老相关基因的表达情况,发现间作种植模式下玉米SGR1、SGR2、VP14和CC2基因在灌浆期和成熟期的表达量均低于玉米净作种植模式下的,而延缓衰老的基因KN1在玉米/大豆2∶2间作种植模式下的表达量略高于玉米净作种植模式下的,这从基因水平证实了玉米/大豆间作能够延缓玉米植株的衰老。

An experiment consisting of two cropping patterns(2-row maize/2-row soybean intercropping and maize monoculture)was conducted to detect the activities of senescence-related enzymes at different growth stages.Expression of maize senescence-related genes at different growth stages were detected by RT-PCR.Results showed that the enzymes activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) were maintained at higher levels, and the contents of chlorophyll, soluble sugar and soluble protein were higher in maize leaves intercropped with soybean, but the content of malondialdehyde (MDA) was decreased, effectively delaying senescence.The expressions of SGR1, SGR2, VP14 and CC2 in intercropped maize at filling and maturity were lower than those in monocultured maize, but the expression of senescence-delaying gene KN1 was higher, confirming that the maize/soybean intercropping could delay maize senescence at gene level.