摘要
研究表明,施钾能够提高作物对蚜虫的抗性,但其机理尚不明确。试验采用营养液培养的方法,设置2 mmol/L和0.005mmol/L KCl两个钾浓度,分析不同钾水平培养下的小麦植株在蚜虫为害后,体内茉莉酸(JA)和水杨酸(SA)的含量和脂氧合酶(LOX)、多酚氧化酶(PPO)、苯丙氨酸解氨酶(PAL)和过氧化物酶(POD)等防御酶活性的变化。结果表明,低钾胁迫显著降低了小麦体内JA和SA的含量,并且诱导LOX和POD酶活性增强,但是对PPO和PAL酶活性没有显著影响。蚜虫为害48 h后,高钾小麦体内JA含量显著高于低钾植株,而SA含量没有明显变化。高钾显著提高了蚜虫为害后小麦叶片中的LOX、PAL、PPO和POD酶活性,而低钾小麦体内4种酶的活性在整个虫害调查期间均没有显著变化。研究表明,充足供钾能够显著提高小麦受到蚜虫为害后体内茉莉酸含量,激活其体内的JA信号传导途径,从而提高防御酶活性,增强其对蚜虫的抵御能力。
Wheat is the second most planted crop in the world and plays an important role in China and the world＇s food security. Aphids are a serious insect pest group for the worldwide wheat growing area and pose a critical threat to wheat yield. It is known that in modern agriculture crop yield largely depends upon fertilizer input, whereas the occurrence of insect herbivores is closely related to the nutrient status in the plant tissues supplied by soil fertility. The prevailing view is that a high potassium level in plant tissues supplied by the soil decreases the occurrence of many pests. Our previous research showed that potassium-deficient wheat had the largest aphid population, whereas the presence of sufficient potassium significantly reduced the aphid population in wheat. So, understanding the relationship between fertilization and the incidence of insect pests is essential for the management of chemical fertilization and insect pests in the modem agroeeosystem. In this paper, the effects of potassium supply on signal molecular contents and defense enzymes activities ofwheat leaves infested by aphids （Sitobion avenae） were investigated. Solution cuhure was used in the experiment and two potassium （K） levels were applied, 2 mmol/L and 0.005 mmol/L KC1, respectively. After 20 d, wheat seedlings were infested by aphids and the signal molecular contents and defense enzymes activities were analyzed over different infestation times. The results showed that K deficiency significantly reduced jasmonic acid （JA） and salicylic acid （SA） content in wheat leaves and increased lipoxygenase （LOX） and polyphenoloxidase （PPO） activities, whereas it had no effects on phenylalnine ammonialyase （PAL） and peroxidase （POD） activities. After 48 h aphid infested, JA content in wheat grown in 2 mM KC1 was significantly increased, 32.2% higher than the no aphid infested control and 50.0% higher than the K- deficient wheat. SA content in K-deficient wheat was significantly increased after aphid infestatio
出处
《生态学报》
CAS
CSCD
北大核心
2014年第10期2539-2547,共9页
Acta Ecologica Sinica
基金
黄淮南部小麦玉米两熟持续丰产高效技术集成创新与示范项目(2011BAD10B07)
粮食作物资源节约型高产技术体系研究项目(2011BAD16B15)
关键词
钾
小麦
蚜虫
茉莉酸
水杨酸
防御酶
potassium
wheat
aphid
jasmonic acid
salicylic acid
defense enzyme
