原位酶谱技术分析旱地长期覆盖下根际酶活性空间分布  

Spatial distribution of enzyme activities in rhizosphere soil under long-term mulching of dryland with in-situ zymography

作　　者：黄冬琳[1] 同斯捷 岳良 李彦 张雪辰[1,2] 郑伟 王朝辉[1] 张绪成[3] 翟丙年 李紫燕[1] Huang Donglin;Tong Sijie;Yue Liang;Li Yan;Zhang Xuechen;Zheng Wei;Wang Zhaohui;Zhang Xucheng;Zhai Bingnian;Li Ziyan(College of Natural Resources and Environment,Northwest A&F University,Yangling 712100,China;Department of Biogeochemistry of Agroecosystems,University of Göttingen,Göttingen 37077,Germany;Key Laboratory of High Water Utilization on Dryland of Gansu Province,Lanzhou 730070,China)

机构地区：[1]西北农林科技大学资源环境学院,杨凌712100 [2]哥廷根大学农业生态系统生物地球化学系,哥廷根37077 [3]甘肃省旱地高水利用重点实验室,兰州730070

出　　处：《农业工程学报》2022年第5期123-130,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家重点研发计划(2021YFD19700);国家自然科学基金(42177342);中央高校基本科研业务费专项资金资助(2452021087)。

摘　　要：根与土壤微生物产生的酶是土壤有机质分解的主要生物驱动因素,对土壤养分循环具有重要意义。该研究利用原位酶谱技术在不破坏作物根系的同时,研究了渭北旱塬长期覆盖春玉米根际土壤酶活性空间分布。田间试验于2020年6月在中国科学院长武黄土高原农业生态试验站进行。以春玉米“先玉335”为供试材料,采用完全随机区组设计,设置秸秆覆盖(SM)、地膜覆盖(FM)和无覆盖(CK)三个处理,于春玉米吐丝期获取根系剖面酶谱图,分析了β-葡萄糖苷酶和亮氨酸氨基肽酶在春玉米根际的分布。结果表明:β-葡萄糖苷酶在秸秆覆盖下根际活性分布(热点)面积最大,是地膜覆盖的1.9倍、无覆盖的8.1倍;同时其在秸秆覆盖下延根分布距离最长为2.5 mm;与之对应,动力学拟合结果也表明秸秆覆盖下的酶动力学参数酶活最大反应速率和米氏常值最大,其土壤底物周转时间最快。亮氨酸氨基肽酶在地膜覆盖下活性分布总面积最大,是秸秆覆盖的1.8倍、无覆盖的6.4倍;其在地膜覆盖下酶活性延根分布距离最长为4.5 mm,秸秆覆盖下的酶动力学参数也为最大,底物周转时间最快。研究揭示了地表覆盖通过调节作物根际土壤酶活性空间分布促进养分吸收,实现旱地玉米高产高效的酶动力学机制。Enzymes produced by roots and soil microorganisms have been the biological driving factors of organic matter decomposition to nutrient cycling in soil.However,the enzyme investigation remains a technical question,due to the heterogeneity of spatial distribution around the roots in the rhizosphere.Soil in-situ zymogram can directly display the distribution enzyme activity by fluorescence mapping.This study aims to investigate the spatial distribution of soil enzyme activities in the rhizosphere of spring maize with different soil surface mulching in Weibei dryland.Taking the spring maize“Xianyu 335”as the research object,a field experiment was carried out without damaging the crop roots by soil in-situ zymogram in June 2020 at the Loess Plateau agroecological experimental station of the Chinese Academy of Sciences.A complete randomized block design was employed with three treatments of Straw Mulching(SM),Plastic Film Mulching(FM),and no-mulching(CK).The in-situ zymography of the root profile was obtained at the silking stage of spring maize.The reaction parameters were calculated with the Michaelis-Menten equation after the enzyme kinetic experiment and simulation.Besides,the correlations between the concentration of enzyme and the soil chemical/physical properties variables were determined for the driving factors of enzyme spatial distribution with the different mulching treatments.The results show that there was the maximum distribution area ofβ-Glucosidase Activity(BG)in the rhizosphere of SM treatment,which was 1.9 times that of plastic film mulching,and 8.1 times that of CK treatment.The longest distance(2.5 mm)along the roots ofβ-glucosidase distribution was found with the SM treatment,which was 0.7 mm further than that with the FM,and 1.5mm further than that with CK.Correspondingly,the kinetic fitting showed that there were the maximum enzyme kinetic parameters V_(max) and k_(m) of SM treatment,which was the fastest turnover time of soil substrate.The total distribution area of Leucine Aminopeptidase

关 键 词：秸秆 膜 酶 空间分布 动力学方程 

分 类 号：S513[农业科学—作物学]