Würsig Henrike, Yim Bunlong, Martín Roldán María, Ghaderi Negar, Stoll Florian, Bouffaud Marie-Lara, Vetterlein Doris, Reitz Thomas, Blagodatskaya Evgenia, Smalla Kornelia, Tarkka Mika
Helmholtz Centre for Environmental Research, 06120 Halle, Germany.
Julius Kühn Institute, 38104 Braunschweig, Germany.
Ann Bot. 2025 Aug 6. doi: 10.1093/aob/mcaf180.
Understanding how annual weather variation, including droughts, affect plant roots and rhizosphere prokaryote dynamics in different years is essential for predicting plant responses to climate fluctuations. This study aimed to investigate the effects of alternating dry and moist years on maize root gene expression and rhizosphere prokaryote composition, and to reveal interactions between the two.
Zea mays B73 wild type (WT) and a root hair deficient mutant (rth3) were grown on two substrates during a three-year field experiment with alternating precipitation, designated as dry, moist, dry. Root gene expression was analyzed between the two dry years and the moist year, supported by superoxide dismutase activity. The rhizosphere was analyzed by measuring the enzyme kinetic parameters of β-glucosidase, acid phosphatase, leucine aminopeptidase and N-acetylglucosaminidase, accompanied by the 16S rRNA-based and 1 - aminocyclopropane - 1 - carboxylate deaminase (acdS+)-based microbial community.
Year was the main driver of root gene expression and the 16S rRNA-based microbial community, with a distinct pattern of drought-responsive genes between dry years and the moist year. Substrate was the main driver of the acdS+-based microbial community and influenced root gene expression and the 16S rRNA-based microbial community, indicating interactive effects between maize roots and rhizosphere prokaryotes. The effect of year and substrate on enzyme kinetics was enzyme specific. Root hair presence had a marginal effect.
This study highlights the role of annual weather variation in shaping root gene expression, rhizosphere prokaryotes and enzyme kinetics and underlines the role of substrate in structuring acdS+-based microbial communities. Our results suggest that plant-microbe interactions are highly sensitive to precipitation variability and might be influenced by repeated maize planting. They emphasize the importance of precipitation history in shaping plant-microbe interactions, which can serve as a basis for drought resilience strategies in agriculture.
了解包括干旱在内的年度天气变化如何影响不同年份植物根系和根际原核生物动态，对于预测植物对气候波动的响应至关重要。本研究旨在调查干湿交替年份对玉米根系基因表达和根际原核生物组成的影响，并揭示两者之间的相互作用。
在为期三年的田间试验中，以交替降水（分别为干旱、湿润、干旱）的方式，在两种基质上种植玉米自交系B73野生型（WT）和根毛缺陷突变体（rth3）。在两个干旱年份和湿润年份之间分析根系基因表达，并辅以超氧化物歧化酶活性。通过测量β-葡萄糖苷酶、酸性磷酸酶、亮氨酸氨肽酶和N-乙酰氨基葡萄糖苷酶的酶动力学参数对根际进行分析，并结合基于16S rRNA和基于1-氨基环丙烷-1-羧酸脱氨酶（acdS+）的微生物群落进行分析。
年份是根系基因表达和基于16S rRNA的微生物群落的主要驱动因素，干旱年份和湿润年份之间存在不同的干旱响应基因模式。基质是基于acdS+的微生物群落的主要驱动因素，并影响根系基因表达和基于16S rRNA的微生物群落，表明玉米根系与根际原核生物之间存在相互作用。年份和基质对酶动力学的影响具有酶特异性。根毛的存在有一定的影响。
本研究突出了年度天气变化在塑造根系基因表达、根际原核生物和酶动力学方面的作用，并强调了基质在构建基于acdS+的微生物群落中的作用。我们的结果表明，植物-微生物相互作用对降水变异性高度敏感，可能受到玉米连作的影响。它们强调了降水历史在塑造植物-微生物相互作用中的重要性，这可为农业抗旱策略提供依据。
