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手性单萜揭示森林排放机制和干旱响应
作者:小柯机器人 发布时间:2022/9/11 16:00:35

德国马普化学所Williams, Jonathan团队报道了手性单萜揭示森林排放机制和干旱响应。相关研究成果发表在2022年9月7日出版的《自然》。

单萜(C10H16)通过植被大量排放到大气中(>100TgC year-1),在大气中,它们很容易与羟基自由基和臭氧反应,形成新的粒子,从而形成云,影响地球的辐射预算,从而影响气候变化。尽管大多数单萜以两种手性镜像形式存在,称为对映体,在测量或建模研究中很少区分这些(+)和()形式。因此,对植物中单萜对映体的单独形成途径及其生态功能了解甚少。

该文中,研究人员展示了在四个月的受控干旱和复湿实验中,在没有紫外线和大气氧化化学的情况下,封闭热带雨林生态系统中对映体分离的大气单萜和异戊二烯数据。令人惊讶的是,排放的对映体显示出明显的diel发射峰,对渐进干燥的响应不同。同位素标记表明,植被主要排放从头合成的()-α-蒎烯,而(+)-α-蒎烯则从储存池排放。随着干旱的加剧,()-α-蒎烯排放源转移到储存池,有利于云的形成。两种α-蒎烯对映体的干旱前混合比与其他单萜的相关性好,表明不同的酶控制。这些结果表明,对映体分布是理解驱动森林生态系统单萜排放的潜在过程和预测气候变化对大气反馈的关键。

附:英文原文

Title: Chiral monoterpenes reveal forest emission mechanisms and drought responses

Author: Byron, Joseph, Kreuzwieser, Juergen, Purser, Gemma, van Haren, Joost, Ladd, S. Nemiah, Meredith, Laura K., Werner, Christiane, Williams, Jonathan

Issue&Volume: 2022-09-07

Abstract: Monoterpenes (C10H16) are emitted in large quantities by vegetation to the atmosphere (>100TgCyear1), where they readily react with hydroxyl radicals and ozone to form new particles and, hence, clouds, affecting the Earth’s radiative budget and, thereby, climate change1,2,3. Although most monoterpenes exist in two chiral mirror-image forms termed enantiomers, these (+) and () forms are rarely distinguished in measurement or modelling studies4,5,6. Therefore, the individual formation pathways of monoterpene enantiomers in plants and their ecological functions are poorly understood. Here we present enantiomerically separated atmospheric monoterpene and isoprene data from an enclosed tropical rainforest ecosystem in the absence of ultraviolet light and atmospheric oxidation chemistry, during a four-month controlled drought and rewetting experiment7. Surprisingly, the emitted enantiomers showed distinct diel emission peaks, which responded differently to progressive drying. Isotopic labelling established that vegetation emitted mainly de novo-synthesized ()-α-pinene, whereas (+)-α-pinene was emitted from storage pools. As drought progressed, the source of ()-α-pinene emissions shifted to storage pools, favouring cloud formation. Pre-drought mixing ratios of both α-pinene enantiomers correlated better with other monoterpenes than with each other, indicating different enzymatic controls. These results show that enantiomeric distribution is key to understanding the underlying processes driving monoterpene emissions from forest ecosystems and predicting atmospheric feedbacks in response to climate change.

DOI: 10.1038/s41586-022-05020-5

Source: https://www.nature.com/articles/s41586-022-05020-5

期刊信息

Nature:《自然》,创刊于1869年。隶属于施普林格·自然出版集团,最新IF:42.778
官方网址:http://www.nature.com/