药剂种子处理对玉米幼苗化学防御反应的影响及机理初探

发布时间：2018-10-09 09:38

【摘要】：植物防御是植物界普遍存在的一种现象,是植物抵抗环境胁迫的主要形式。植物防御受遗传因素控制,但是在不同的环境因素的诱导下,会产生不同的防御反应。植物化学防御主要是通过调节体内防御酶活性和次生代谢物含量来抵抗环境胁迫。本文使用吡虫啉和戊唑醇两种悬浮种衣剂分别处理蠡玉35、圣瑞999和奥玉21三个玉米品种,研究了使用两种悬浮种衣剂拌种时,植物幼苗内防御体系的变化规律。通过测定CAT、POD和PPO三种防御酶的活性和植物防御物质(对羟基苯甲酸、咖啡酸、肉桂酸、丁香酸、香豆酸、水扬酸、阿魏酸和香草酸)含量的变化,来研究这两种悬浮种衣剂对玉米防御体系的影响,同时检测植物防御有关物质(丁布、酚酸和防御蛋白)基因表达量的变化,分析不同玉米品种在这两种悬浮种衣剂拌种处理后,植物防御能力变化的情况。这对指导使用拌种剂与植物自身防御能力相结合,提高植物的防虫抗病能力有实际意义。本次试验主要的研究结果如下:(1)蠡玉35、圣瑞999和奥玉21在使用吡虫啉或戊唑醇拌种处理后,植物幼苗内过氧化氢酶的活性明显增加(使用吡虫啉后,第8天时比对照组分别增大了3.6倍、2.3倍和2.8倍,使用戊唑醇后分别增大了2.4倍、3.2倍和2.3倍)。POD和PPO的活性变化相对复杂,第8天时蠡玉35在使用吡虫啉拌种后POD的活性升高了62.6%,其它处理组的POD的活性都降低,不过在第18天时POD的活性也逐渐接近对照组活性。奥玉21经吡虫啉拌种处理后,第8天时PPO活性增加了37.5%,其它处理组的PPO均降低,其中圣瑞999幼苗叶片内PPO活性受这两种药剂的抑制作用较强,吡虫啉拌种在第12天时PPO活性下降了33.3%,戊唑醇拌种在第8天时PPO活性下降26.3%。(2)蠡玉35使用吡虫啉拌种后,检测出的五种酚酸中,丁香酸和阿魏酸的含量显著降低,第8天时分别比对照组降低了10.31μg/g和4.3μg/g,而第18天时接近对照组含量。在使用戊唑醇拌种后,咖啡酸和阿魏酸含量下降了3.39μg/g和6.31μg/g,在第18天时,咖啡酸的含量逐渐恢复正常。圣瑞999在使用吡虫啉拌种后所检测到的五种酚酸含量均高于对照组含量。经戊唑醇拌种剂拌种后,圣瑞999幼苗咖啡酸和阿魏酸含量虽然有所下降,但在第10天时已经恢复正常水平。吡虫啉拌种处理奥玉21后,五种酚酸含量均下降,其中对丁香酸和阿魏酸含量影响最大,在18天时比对照组降低了2.64μg/g和3.09μg/g。在使用戊唑醇拌种后,该品种幼苗内只阿魏酸含量降低,且能在较短时间回复正常水平,而其它四种酚酸含量上升。(3)蠡玉35在使用吡虫啉拌种后,第18天时Bx1、Bx6和PR-2a基因表达量分别下调3.89倍、3.67倍和1.5倍,其它基因表达量均上调,丁布和直接防御蛋白的合成减少,而总酚和间接防御物质的合成增加;使用戊唑醇拌种后,第18天,Bx6、MPI、TPS和FPS表达下调4.04倍、2.09倍、1.15倍和2.43倍,丁布、直接防御蛋白、间接防御物质的合成减少,对总酚合成增加;圣瑞999使用吡虫啉后,丁布、总酚、直接防御蛋白和间接防御物质的合成都增加,使用戊唑醇拌种后,在14天时,只有PR-2a表达下调3.01倍,丁布、总酚、间接防御物质的合成增加,直接防御蛋白合成减少;奥玉21使用吡虫啉拌种后,第18天时,只有PAL表达下调3.48倍,丁布、直接防御蛋白和间接防御物质合成有促进作用,总酚的合成受到抑制,在使用戊唑醇拌种后,18天时Bx6、TPS和FPS表达下调,丁布、间接防御物质受到抑制,对总酚和直接防御蛋白的合成有促进作用。
[Abstract]:Plant defense is a ubiquitous phenomenon in the plant community, which is the main form of plant resistance to environmental stress. Plant defense is controlled by genetic factors, but under the guidance of different environmental factors, different defense responses can be generated. Plant chemical defense is mainly to resist environmental stress by regulating the activity of defense enzymes and the content of secondary metabolites in vivo. This paper deals with the changes of the defense system in plant seedlings when two kinds of suspension seed dressing agents were used to treat the three maize varieties, namely, Yuyu 35, Shengrui 999 and Oyu 21, respectively. The effects of these two kinds of suspending agents on the maize defense system were studied by measuring the activities of CAT, POD and PPO and the changes of plant defense substances (p-Hydroxybenzoic acid, caffeic acid, cinnamic acid, Syringic acid, Xiangdou acid, water-soluble acid, ferulic acid and fragrant oxalic acid). At the same time, the changes of gene expression of plant defense related substances (butylphenol, phenolic acid and defense protein) were detected, and the changes of plant defense ability were analyzed. This is of practical significance to guide the use of anti-virus agent in combination with plant's defense ability, and to improve the insect-resistant and disease-resistant ability of plants. The main results of this experiment were as follows: (1) The activity of catalase in plant seedlings was obviously increased after the treatment with oxytetracycline or pentosan alcohol, and the activity of catalase in plant seedlings increased by 3. 6 times, 2. 3 and 2. 8 times higher than that of the control group. (2. 4 times, 3. 2 and 2. 3 times respectively) were increased after the use of pentode alcohol. The activities of POD and PPO were relatively complex, and the activity of POD was increased by 62. 6% and the activity of POD in other treatment groups decreased at day 8. However, POD activity gradually approached the activity of control group on day 18. The PPO activity increased by 37. 5% on day 8 and PPO activity in other treatment groups decreased, and the PPO activity decreased by 33.3% at the 12th day. The activity of PPO decreased by 26. 3% on day 8. (2) The content of Syringic acid and ferulic acid in the five phenolic acids detected was significantly lower than that of the control group at day 8, and the contents of the five phenolic acids were decreased by 10. 31 ug/ g and 4. 3 ug/ g respectively on day 8, and the content of the control group was close to the control group at day 18. The content of caffeic acid and ferulic acid decreased by 3.39 & mu; g/ g and 6.31 & mu; g/ g after use of sodium pentode, and the content of caffeic acid recovered gradually on day 18. The content of five phenolic acids was higher than that of the control group after the use of carvedilol. The content of caffeic acid and ferulic acid in the seedlings of St. Rainy's 999 seedlings decreased, but returned to normal level at day 10. After treatment of Oyu 21, the content of five phenolic acids decreased, in which the content of clove acid and ferulic acid was the largest, and the content of five phenolic acids decreased by 2.64 ug/ g and 3.09 ug/ g at 18 days. In addition, the content of ferulic acid in the seedling was decreased, and the content of other four phenolic acids increased in short time. (3) The expression levels of Bx1, Bx6 and PR-2a were decreased by 3.89, 3.67 and 1. 5 times respectively on day 18, and the expression levels of other genes were up-regulated. The expression of Bx6, MPI, TPS and FPS was decreased by 4.04 fold, 2.09 times, 1. 15 fold and 2.43 fold, 2. 09 times, 1. 15 fold and 2. 43 fold, 2. 09 times, 1. 15 fold, and 2. 43 fold, 2. 09 times, 1. 15 fold and 2. 43 fold, and the total phenol synthesis was increased. The synthesis of direct defense protein and indirect defense material was increased, and the expression of PR-2a was decreased by 3. 01 times on 14 days after use of pentode alcohol. only the PAL expression is down regulated by 3.48 times, the synthesis of the butylphenol, the direct defense protein and the indirect defense material is promoted, the synthesis of the total phenol is inhibited, It can promote the synthesis of total phenol and direct defense protein.
【学位授予单位】：河南科技学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S513;S351.1

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