Photosynthesis and fluorescence responses of Jatropha curcas to chilling and freezing stress during early vegetative stages
Photosynthesis and fluorescence responses of Jatropha curcas to chilling and freezing stress during early vegetative stages
复制标题
DOI：
10.1016/j.envexpbot.2014.02.005
复制
发表时间：
2014-06-01
影响因子：
5.7
通讯作者：
Insausti, P.
中科院分区：
文献类型：
--
作者：
Ploschuk, E. L.;Bado, L. A.;Insausti, P.
小桐子是生产生物柴油的理想树种。低温和冰冻胁迫是其建立的主要环境制约因素，其主要原因是对叶片光合机构的伤害。本研究旨在评估低温（4 ℃下40 h）和冷冻（-1 ℃、-2 ℃和-3 ℃下2 h）对最大叶片光合作用（A（max））的影响，并与气孔导度（g（s））和光化学活性相关。在室外的盆中进行两个类似的实验;在气候室中在每株植物四片展开叶的阶段进行处理，然后返回室外。在处理结束后1天和30天（DAT）测量叶片气体交换、水分状况和荧光变量。在1 DAT，Amax和g，降低高达75%和100%，分别在冷却和冷冻处理。然而，胞间CO2浓度（CO）显示出相反的模式，放弃了Amax降低的决定性作用。低温和冰冻胁迫下植物光合作用的电子利用效率较低。PSII的潜在效率（Fv/Fm）、叶绿素含量（Ch 1）和相对含水量（RWC）仅受低温处理的影响，而低温和中低温处理的非光化学猝灭（NPQ）增加。最低冷冻处理导致叶片死亡，而存活植株在30 DAT时还观察到对Amax g（s）和电子传递速率（ETR）的几种残留效应。这项工作揭示了参与光合作用的寒冷和冷冻伤害消耗的决定性过程，揭示了低温对J. curcas作物建立具有持久和有害的影响。(C)2014爱思唯尔有限公司版权所有。
Jatropha curcas is a promissory species for biodiesel production. Chilling and freezing stress are major environmental constraints for its establishment as a result of the injury provoked on leaf photosynthetic apparatus. This study is aimed at evaluating the impact of chilling (40h at 4 degrees C) and freezing (2h at -1, -2 and -3 degrees C) on maximum leaf photosynthesis (A(max)), in relation to stomatal conductance (g(s)) and photochemical activity. Two similar experiments were conducted in pots outdoors; treatments were performed in climate chambers at the stage of four expanded leaves per plant, and then returned outdoors. Leaf gas exchange, water status and fluorescence variables were measured at 1 and 30 days after the end of the treatments (DAT). At 1 DAT, Amax and g, were reduced up to 75% and 100% in chilling and freezing treatments, respectively. However, the intercellular CO2 concentration (CO showed an inverse pattern, discarding a determinant role in Amax reductions. A lower efficiency electron use for photosynthesis was detected for plants subjected to chilling and freezing stress. The potential efficiency of PSII (Fv/Fm), chlorophyll content (Ch1) and relative water content (RWC) were only affected by the lowest freezing treatments, while chilling and intermediate freezing plants showed an increase of the non photochemical quenching (NPQ). Leaf death occurred in the lowest freezing treatments, while several residual effects on Amax g(s) and electron transport rate (ETR) were also observed at 30 DAT in the survival plants. This work sheds light on the determinant processes involved in the depletion of photosynthesis by chilling and freezing injuries, revealing that low temperatures have persistent and detrimental effects on J. curcas crop establishment. (C) 2014 Elsevier B.V. All rights reserved.