Purpose

Droughts and heat waves are expected to occur in combination more frequently under climate change; however, the interactive effect of these extreme events on soil microorganisms remains poorly understood. Here, we investigated the effects of drought, heat wave, and rehydration on bacterial diversity and community composition in Solanum lycopersicum grown soil.

Materials and methods

A growth chamber experiment with two factors (drought and heat wave) was conducted. Seedlings of Solanum lycopersicum were grown in well-watered or moderate drought stress at ambient temperature prior to a 7-day heat wave treatment. Rewatering from drought was conducted after the heat wave treatment. Soils were sampled at three time points, and bacterial 16S ribosomal RNA genes extracted from total soil DNA were amplified by PCR.

Results and discussion

Results showed that heat wave significantly affected bacterial diversity and community composition, while drought only significantly affected community composition. Their combination had significant interactive effect on diversity but not community composition. Moderate drought slightly increased bacterial diversity, but heat wave plus drought caused a decline in diversity. Heat wave stress suppressed the recovery of bacterial diversity from drought stress.

Conclusions

Our results suggest that heat wave can aggravate the effect of drought on soil bacterial diversity, and the combination of heat wave and drought stress causes a lower recovery potential for bacterial diversity, indicating that extreme weather events would strongly affect belowground bacterial community composition in future climatic scenarios.

中文翻译：

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热浪加剧了干旱对番茄茄属土壤中细菌多样性的影响，但对群落组成没有影响

目的

在气候变化下，干旱和热浪预计会更频繁地发生。然而，这些极端事件对土壤微生物的相互作用影响知之甚少。在这里，我们调查了干旱，热浪和补水对番茄生长土壤中细菌多样性和群落组成的影响。

材料和方法

进行了具有两个因素（干旱和热浪）的生长室实验。在进行7天的热浪处理之前，在环境温度充足或适度的干旱胁迫下生长番茄茄（Solanum lycopersicum）的幼苗。热浪处理后，进行干旱补水。在三个时间点对土壤取样，并通过PCR扩增从土壤总DNA中提取的细菌16S核糖体RNA基因。

结果和讨论

结果表明，热浪显着影响细菌的多样性和群落组成，而干旱仅显着影响群落组成。他们的结合对多样性具有显着的互动影响，但对社区组成没有影响。中度干旱稍微增加了细菌多样性，但热浪加干旱导致多样性下降。热浪胁迫抑制了干旱胁迫下细菌多样性的恢复。

结论

我们的结果表明，热浪会加剧干旱对土壤细菌多样性的影响，并且热浪和干旱胁迫的结合会降低细菌多样性的恢复潜力，这表明极端天气事件将在未来的气候中强烈影响地下细菌群落的组成。场景。