Photosynthetic apparatus in primary leaves of barley seedlings grown under blue or red light of very low photon flux densities
Photosynthetic apparatus in primary leaves of barley seedlings grown under blue or red light of very low photon flux densities
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在极低光子通量密度的蓝光或红光下生长的大麦幼苗初生叶的光合装置
DOI：
10.1023/a:1006281321925
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发表时间：
1999
影响因子：
3.7
通讯作者：
T. Krendeleva
中科院分区：
文献类型：
--
作者：
N. Bukhov;V. Makarova;V. Bondar;I. Drozdova;E. Egorova;Lyudmila Kotova;A. Kotov;T. Krendeleva
研究了蓝光（BL）和红光（RL）对大麦幼苗初生叶叶绿素（Chl）a和Chl B含量、CO2气体交换速率、叶绿素荧光猝灭系数和内源激素的影响。光子通量密度（PFD）在0.3和12 μmol m-2s-1之间。在0.3 μmol m-2s-1的PFD条件下生长的植物，与12 μmol m-2s-1条件下生长的植物相比，在BL条件下叶绿素含量降低了10倍，在RL条件下降低了3倍。叶绿素a/B比值在BL中从2.3-2.5增加到4.4-4.5，而在RL中没有，在植物培养中PFD从12 μmol m-2s-1减少到0.3 μmol m-2s-1。在弱BL条件下，植物的光合CO2吸收速率降低了几倍，而在RL条件下，PFD从12 μmol m-2s-1降低到0.3 μmol m-2s-1时，光合速率仅下降20%。在植物培养过程中PFD的减少减少，在BL，而不是在RL叶片的光合作用的最大量子产额。在植物栽培过程中，根据吸收量子数计算的叶绿素荧光的非光化学和光化学猝灭的光响应曲线不受RL的PFD的影响。相反，无论是非光化学猝灭和积累的QA-，减少光系统II的初级受体，发生在较低的吸收量子在BL植物叶片中生长在0.3比12 μmol m-2s-1。在低PFDs范围内，光合机构的发育受光调控，可能有两种光调节反应。RL的极低PFDs饱和的光调节反应被认为是由光敏色素介导的。光敏色素被认为能增强（与类囊体的其他色素-蛋白质复合物有关）光系统II（LHC II）的叶绿素-b结合捕光复合物的积累。它的作用独立于介导第二光调节反应的色素，如在混合蓝光加红光下植物生长的实验结果所证明的。叶片中细胞分裂素和吲哚-3-乙酸的含量不受光质和PFD的显着影响，从而表明这些植物激素不参与光调节过程。
Chlorophyll (Chl) a and Chl b contents, rate of CO2gas exchange, quenching coefficients of chlorophyll fluorescence, and endogenous phytohormones have been studied in primary leaves of barley seedlings cultivated under blue (BL) or red (RL) light. Photon flux densities (PFD) were between 0.3 and 12 μmol m-2s-1. Plants grown at PFD of 0.3 μmol m-2s-1demonstrated in BL tenfold and in RL threefold decreased Chl content compared to plants grown at 12 μmol m-2s-1. Chl a/b ratio increased from 2.3–2.5 to 4.4–4.5 in BL, not in RL, following the decrease in PFD at plant cultivation from 12 to 0.3 μmol m-2s-1. Plants cultivated at weak BL demonstrated severalfold decreased rate of photosynthetic CO2uptake, whereas decrease in PFD of RL from 12 to 0.3 μmol m-2s-1caused only 20% de cline in the rate of photosynthesis. Decrease in PFD during a plant cultivation reduced the maximum quantum yield of photosynthesis in BL, not in RL leaves. Light response curves of non-photochemical and photochemical quenching of chlorophyll fluorescence calculated on the basis of absorbed quanta were not affected by PFD of RL during plant cultivation. On the contrary, both non-photochemical quenching and accumulation of QA-, reduced primary acceptor of Photosystem II, occurred at lower amounts of absorbed quanta in leaves of BL plants grown at 0.3 than at 12 μmol m-2s-1. Two photoregulatory reactions were suggested to exert the light control of the development of photosynthetic apparatus in the range of low PFDs. The photoregulatory reaction saturating by very low PFDs of RL was supposed to be mediated by phytochrome. Phytochrome was proposed to enhance (as related to other pigment-protein complexes of thylakoids) the accu mulation of chlorophyll- b-binding light-harvesting complex of Photosystem II (LHC II). It acts independently of the pigment mediating the second photoregulatory reaction, as evidenced by the results of experiments with plant growth under mixed blue plus red light. The contents of cytokinins and indole-3-acetic acid in a leaf were not significantly affected by either light quality and PFD thus indicating those phytohormones not to be involved into photoregulatory processes.