Passive CO2 concentration in higher plants.
Passive CO2 concentration in higher plants.
复制标题
高等植物中的被动二氧化碳浓度。
DOI：
10.1016/j.pbi.2016.03.016
复制
发表时间：
2016
影响因子：
9.5
通讯作者：
R. Khoshravesh
中科院分区：
文献类型：
--
作者：
R. Sage;R. Khoshravesh
植物可以在不额外消耗ATP的情况下浓缩CO2。这发生在光呼吸/呼吸CO2在内部隔室中释放时。隔室中的叶绿体看到CO2升高，增强Rubisco活性。这种机制可以在最近的低CO2事件中维持C3植物。在温暖的低CO2条件下，光呼吸对C3光合作用的限制是显著的。为了补偿，某些植物进化出了利用ATP支持的CO2泵（如C4光合作用）主动将CO2聚集在Rubisco周围的机制。植物也可以被动地积累CO2，而不需要额外的ATP消耗，通过将光呼吸和呼吸CO2的释放定位在Rubisco周围，Rubisco与周围的空气空间扩散隔离。光呼吸CO2的被动积累发生在甘氨酸脱羧酶定位于维管鞘细胞的C2光合作用中，并通过在叶肉细胞周围形成叶绿体鞘。外周鞘需要光呼吸的CO2重新进入叶绿体，在那里它可以被重新固定。呼吸CO2的被动积累是常见的器官，如茎，果实和花，由于丰富的异养组织和高扩散阻力沿着器官周边。这些器官中的叶绿体能够利用这种高CO2来减少光呼吸。根和根茎呼吸的CO2也可以通过气孔、通气组织和木质部流进入茎和叶的光合细胞，从而被动地增加CO2浓度。通过被动的CO2浓度，C3物种可能会提高其碳经济性，并在低大气CO2的事件保持健身。
HighlightsPlants can concentrate CO 2 without additional expenditure of ATP.This occurs when photorespired/respired CO 2 are released in internal compartments.Chloroplasts in the compartments see elevated CO 2, enhancing Rubisco activity.Such mechanisms could sustain C 3 plants during low CO 2 episodes of recent time.Photorespiratory limitations on C 3 photosynthesis are substantial in warm, low CO 2 conditions. To compensate, certain plants evolved mechanisms to actively concentrate CO 2 around Rubisco using ATP-supported CO 2 pumps such as C 4 photosynthesis. Plants can also passively accumulate CO 2 without additional ATP expenditure by localizing the release of photorespired and respired CO 2 around Rubisco that is diffusively isolated from peripheral air spaces. Passive accumulation of photorespired CO 2 occurs when glycine decarboxylase is localized to vascular sheath cells in what is termed C 2 photosynthesis, and through forming sheaths of chloroplasts around the periphery of mesophyll cells. The peripheral sheaths require photorespired CO 2 to re-enter chloroplasts where it can be refixed. Passive accumulation of respiratory CO 2 is common in organs such as stems, fruits and flowers, due to abundant heterotrophic tissues and high diffusive resistance along the organ periphery. Chloroplasts within these organs are able to exploit this high CO 2 to reduce photorespiration. CO 2 concentration can also be enhanced passively by channeling respired CO 2 from roots and rhizomes into photosynthetic cells of stems and leaves via lacunae, aerenchyma and the xylem stream. Through passive CO 2 concentration, C 3 species likely improved their carbon economy and maintained fitness during episodes of low atmospheric CO 2.
影响因子：
64.5
作者：
Heckmann, David;Schulze, Stefanie;Lercher, Martin J.
通讯作者：
Lercher, Martin J.
影响因子：
11.6
作者：
Stefanie Schulze;Julia Mallmann;Janet Burscheidt;Maria Koczor;M. Streubel;H. Bauwe;U. Gowik;P. Westhoff
通讯作者：
Stefanie Schulze;Julia Mallmann;Janet Burscheidt;Maria Koczor;M. Streubel;H. Bauwe;U. Gowik;P. Westhoff