Can chlorophyll-a fluorescence parameters be used as bio-indicators to distinguish between drought and salinity stress in Tilia cordata Mill?
Can chlorophyll-a fluorescence parameters be used as bio-indicators to distinguish between drought and salinity stress in Tilia cordata Mill?
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DOI：
10.1016/j.envexpbot.2017.11.001
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发表时间：
2018-08-01
影响因子：
5.7
通讯作者：
Sitko, Krzysztof
中科院分区：
文献类型：
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作者：
Kalaji, Hazem M.;Rackova, Lydia;Sitko, Krzysztof
叶绿素a荧光测量已被用于（多年来）研究各种植物的光合机制的功能和性能。然而，最近只有很少的研究表明该工具可以用于识别影响或/和限制植物生长的胁迫因素。本研究的目的是确定叶绿素荧光参数，可用于指示干旱或/和盐胁迫的紫椴。在温室中，在半控制条件下，将盆栽幼苗（1- 1.5m高，直径2- 3cm的树干）暴露于干旱胁迫或盐胁迫4周。在胁迫处理期间，每周进行四次叶绿素a荧光测量。基于OJIP瞬态曲线的荧光参数进行了计算，以确定它们中的哪一个受到干旱和/或盐度的影响。我们发现，盐和干旱有类似的光依赖光合作用阶段的作用机制，但光系统H的响应施加胁迫发生在干旱胁迫的植物。变化表现为对放氧复合物和反应中心的损害，同时增加耗散能量。由于这两种胁迫因素诱导类似的光抑制的影响，光依赖的光合作用阶段，叶绿素a荧光工具不能推荐作为一个生物指示剂，以区分干旱和盐胁迫的影响，在椴树。
Chlorophyll-a fluorescence measurements have been used (for many years) to study the function and performance of photosynthetic machinery of various plants. However, only few recent works have shown that this tool can be useful to identify stress factor that affects or/and limits plant growth. The aim of our research was to identify chlorophyll fluorescence parameters which can be used as indicators to drought or/and salinity stress in Tilia cordata Mill. Young potted trees (1-1.5 m high with a trunk of 2-3 cm in diameter) were exposed to drought stress or salinity stress for 4 weeks under semi controlled conditions in a greenhouse. Chlorophyll a fluorescence measurements were conducted every week four times during the stress treatment. The fluorescence parameters based on OJIP transient curves were calculated in order to ascertain which of them was affected by drought and/ or salinity. We found that salinity and drought had similar mechanisms of action on the light-depend photosynthesis phase, however the response of photosystem H to applied stress occurred earlier in drought-stressed plants. Changes appeared as damage to the oxygen-evolving complex and reaction centres with a simultaneous increase in dissipated energy. Since both stress factors induced similar photo-inhibitory influence on the light-depending photosynthesis phase, the chlorophyll-a fluorescence tool cannot be recommended as a bio-indicator to distinguish between drought and salinity stress effects in Tilia cordata Mill.