Li Yingao, Lu Jiading, Dong Chunyang, Wang Haojie, Liu Boshuai, Li Defeng, Cui Yalei, Wang Zhichang, Ma Sen, Shi Yinghua, Wang Chengzhang, Zhu Xiaoyan, Sun Hao
Henan Key Laboratory of Innovation and Utilization of Grassland Resources, College of Animal Science and Technology, Henan Agricultural University, Zhengzhou, China.
Front Microbiol. 2024 Aug 16;15:1447348. doi: 10.3389/fmicb.2024.1447348. eCollection 2024.
Atrazine, a commonly employed herbicide for corn production, can leave residues in soil, resulting in photosynthetic toxicity and impeding growth in subsequent alfalfa ( L.) crops within alfalfa-corn rotation systems. The molecular regulatory mechanisms by which atrazine affects alfalfa growth and development, particularly its impact on the microbial communities of the alfalfa rhizosphere, are not well understood. This study carried out field experiments to explore the influence of atrazine stress on the biomass, chlorophyll content, antioxidant system, and rhizosphere microbial communities of the atrazine-sensitive alfalfa variety WL-363 and the atrazine-resistant variety JN5010. The results revealed that atrazine significantly reduced WL-363 growth, decreasing plant height by 8.58 cm and root length by 5.42 cm ( < 0.05). Conversely, JN5010 showed minimal reductions, with decreases of 1.96 cm in height and 1.26 cm in root length. Chlorophyll content in WL-363 decreased by 35% under atrazine stress, while in JN5010, it was reduced by only 10%. Reactive oxygen species (ROS) accumulation increased by 60% in WL-363, compared to a 20% increase in JN5010 ( < 0.05 for both). Antioxidant enzyme activities, such as superoxide dismutase (SOD) and catalase (CAT), were significantly elevated in JN5010 ( < 0.05), suggesting a more robust defense mechanism. Although the predominant bacterial and fungal abundances in rhizosphere soils remained generally unchanged under atrazine stress, specific microbial groups exhibited variable responses. Notably, abundance declined in WL-363 but increased in JN5010. FAPROTAX functional predictions indicated shifts in the abundance of microorganisms associated with pesticide degradation, resistance, and microbial structure reconstruction under atrazine stress, displaying different patterns between the two varieties. This study provides insights into how atrazine residues affect alfalfa rhizosphere microorganisms and identifies differential microbial responses to atrazine stress, offering valuable reference data for screening and identifying atrazine-degrading bacteria.
莠去津是玉米生产中常用的除草剂，它会在土壤中残留，导致光合毒性，并阻碍苜蓿 - 玉米轮作系统中后续苜蓿作物的生长。莠去津影响苜蓿生长发育的分子调控机制，尤其是其对苜蓿根际微生物群落的影响，目前尚不清楚。本研究开展了田间试验，以探究莠去津胁迫对莠去津敏感型苜蓿品种WL - 363和抗莠去津品种JN5010的生物量、叶绿素含量、抗氧化系统及根际微生物群落的影响。结果表明，莠去津显著降低了WL - 363的生长，株高降低了8.58厘米，根长降低了5.42厘米（P < 0.05）。相反，JN5010的降幅最小，株高降低了1.96厘米，根长降低了1.26厘米。在莠去津胁迫下，WL - 363的叶绿素含量下降了35%，而JN5010仅下降了10%。WL - 363中的活性氧（ROS）积累增加了60%，相比之下，JN5010增加了20%（两者P < 0.05）。超氧化物歧化酶（SOD）和过氧化氢酶（CAT）等抗氧化酶活性在JN5010中显著升高（P < 0.05），表明其防御机制更强。尽管在莠去津胁迫下根际土壤中主要细菌和真菌的丰度总体保持不变，但特定微生物类群表现出不同的反应。值得注意的是，[具体微生物类群名称]在WL - 363中的丰度下降，但在JN5010中增加。FAPROTAX功能预测表明，在莠去津胁迫下，与农药降解、抗性及微生物结构重建相关的微生物丰度发生了变化，两个品种呈现出不同的模式。本研究深入了解了莠去津残留如何影响苜蓿根际微生物，并确定了微生物对莠去津胁迫的不同反应，为筛选和鉴定莠去津降解细菌提供了有价值的参考数据。
