Larbi Ajmi, Abadía Anunciación, Abadía Javier, Morales Fermín
Department of Plant Nutrition, Aula Dei Experimental Station, Spanish Council for Scientific Research (CSIC), Apdo. 202, Zaragoza, E-50080, Spain.
Photosynth Res. 2006 Sep;89(2-3):113-26. doi: 10.1007/s11120-006-9089-1. Epub 2006 Sep 13.
The regulation of photosynthesis through changes in light absorption, photochemistry, and carboxylation efficiency has been studied in plants grown in different environments. Iron deficiency was induced in sugar beet (Beta vulgaris L.) by growing plants hydroponically in controlled growth chambers in the absence of Fe in the nutrient solution. Pear (Pyrus communis L.) and peach (Prunus persica L. Batsch) trees were grown in field conditions on calcareous soils, in orchards with Fe deficiency-chlorosis. Gas exchange parameters were measured in situ with actual ambient conditions. Iron deficiency decreased photosynthetic and transpiration rates, instantaneous transpiration efficiencies and stomatal conductances, and increased sub-stomatal CO(2) concentrations in the three species investigated. Photosynthesis versus CO(2) sub-stomatal concentration response curves and chlorophyll fluorescence quenching analysis revealed a non-stomatal limitation of photosynthetic rates under Fe deficiency in the three species investigated. Light absorption, photosystem II, and Rubisco carboxylation efficiencies were down-regulated in response to Fe deficiency in a coordinated manner, optimizing the use of the remaining photosynthetic pigments, electron transport carriers, and Rubisco.
通过改变光吸收、光化学和羧化效率来调节光合作用，这一过程已在生长于不同环境中的植物中得到研究。通过在可控生长室中无铁营养液水培的方式，诱导甜菜（Beta vulgaris L.）缺铁。梨树（Pyrus communis L.）和桃树（Prunus persica L. Batsch）生长于石灰性土壤的田间条件下，果园存在缺铁黄化现象。在实际环境条件下原位测量气体交换参数。缺铁降低了所研究的这三种植物的光合速率、蒸腾速率、瞬时蒸腾效率和气孔导度，并提高了胞间二氧化碳浓度。光合速率与胞间二氧化碳浓度响应曲线以及叶绿素荧光猝灭分析表明，在所研究的三种植物中，缺铁情况下光合速率存在非气孔限制。光吸收、光系统II和核酮糖-1,5-二磷酸羧化酶羧化效率会因缺铁而协同下调，从而优化剩余光合色素、电子传递载体和核酮糖-1,5-二磷酸羧化酶的利用。
