Exploiting the potential of plants with crassulacean acid metabolism for bioenergy production on marginal lands
Exploiting the potential of plants with crassulacean acid metabolism for bioenergy production on marginal lands
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DOI：
10.1093/jxb/erp118
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发表时间：
2009-07-01
影响因子：
6.9
通讯作者：
Smith, J. Andrew C.
中科院分区：
文献类型：
--
作者：
Borland, Anne M.;Griffiths, Howard;Smith, J. Andrew C.
景天酸代谢是一种光合作用适应，促进夜间CO2的吸收，从而优化生长在干旱生境中的植物碳同化的水分利用效率。一些CAM物种在边缘生境进行了农艺开发，显示出与水分利用效率最高的C-3或C-4作物相当的年地上生产力，但只有耕作所需水量的20%。这些属性突出了CAM植物在碳固存方面的潜力，以及作为边际和退化土地上生产生物能源的原料的潜力。这篇综述着重介绍了在缺水环境中促进高生物量生产的CAM的代谢和形态特征。支撑CAM的羧化过程的时间分离为调节昼夜碳增量提供了灵活性，并在新陈代谢、生长和生产力的昼夜控制方面提出了基本问题。高储水容量所赋予的优势，转化为缓冲环境可用水的波动的能力，必须与多肉的CAM组织对二氧化碳供应到碳同化的细胞部位施加的扩散(气孔和内部)限制进行交易。最大化CAM生物量和碳固存的可行性需要通过潜在的分子、生理和生态过程来了解。根据实现系统水平理解的需要，概述和讨论了在开发CAM遗传模型方面的最新进展，该系统水平的理解跨越了对该途径的分子控制，一直到CAM的农艺性能和在边际土地上提供生态系统服务。
Crassulacean acid metabolism (CAM) is a photosynthetic adaptation that facilitates the uptake of CO2 at night and thereby optimizes the water-use efficiency of carbon assimilation in plants growing in arid habitats. A number of CAM species have been exploited agronomically in marginal habitats, displaying annual above-ground productivities comparable with those of the most water-use efficient C-3 or C-4 crops but with only 20% of the water required for cultivation. Such attributes highlight the potential of CAM plants for carbon sequestration and as feed stocks for bioenergy production on marginal and degraded lands. This review highlights the metabolic and morphological features of CAM that contribute towards high biomass production in water-limited environments. The temporal separation of carboxylation processes that underpins CAM provides flexibility for modulating carbon gain over the day and night, and poses fundamental questions in terms of circadian control of metabolism, growth, and productivity. The advantages conferred by a high water-storage capacitance, which translate into an ability to buffer fluctuations in environmental water availability, must be traded against diffusive (stomatal plus internal) constraints imposed by succulent CAM tissues on CO2 supply to the cellular sites of carbon assimilation. The practicalities for maximizing CAM biomass and carbon sequestration need to be informed by underlying molecular, physiological, and ecological processes. Recent progress in developing genetic models for CAM are outlined and discussed in light of the need to achieve a systems-level understanding that spans the molecular controls over the pathway through to the agronomic performance of CAM and provision of ecosystem services on marginal lands.