Acclimatization of Photosynthetic Apparatus of Tor Grass (Brachypodium pinnatum) during Expansion

Abstract

The aim of this study was to understand the acclimatization mechanisms of photosynthetic apparatus in Brachypodium pinnatum (L.) P. Beauv grass during its expansion. Twelve populations differentiated by age: young (30–50 years old), intermediate age (ca. 100 y) and old (>300 y) were studied. It was confirmed that the decrease of the number of genotypes as a result of environmental stress and competition were reflected in changes in chlorophyll fluorescence (ChlF) parameters. The old stands were dominated by a few genotypes which seem to be the best acclimatized to the self-shading/competition by lowering their photosynthetic performance during light-phase of photosynthesis. On the other hand, the 'high-speed' photosynthetic rate observed in the young populations can be seen as acclimatization to very adverse conditions. Our results clearly confirm that ChlF is a powerful method of inferring physiological mechanisms of the expansion of tor grass. The Principal Component and Redundancy Analyses, followed with k-means classification, allowed to find the differentiation of groups of distinct ChlF parameters and enabled us to relate them to changes in genotypic diversity of populations. We conclude that the plastic morphological and physiological response to changeable habitat light conditions with its optimum in half-shade refers to its forest-steppe origin.

Responses of photosynthetic apparatus in sunflower cultivars to combined drought and salt stress

“…The lower JIP curve in Hysun-33 and Hysun-39 indicated the accumulation of inactive reaction centers of PSII as compared to S.28111 and SF0049 under combined stress. Insignificant changes at 'O' step indicated that there was a little or no loss of energy transfer to reaction centers from antenna complex (Baker 2008). This may be due to higher number of inactive reaction centers (lower peak) where electrons cannot be transferred from reduced plastoquinone (QA -) or LHCII to PSII core (Murkowski 2002).…”

“…It was expected that Chl fluorescence can be used for a fast assessment of cultivar acclimatization and can be helpful in management and planning (Bąba et al 2016). The common effects of combined salt and drought stresses on growth and development of oil seed crop plants, such as sunflower and soybean, have been reported but their photochemical efficiency through Chl a fluorescence is not well established.…”

Special issue in honour of Prof. Reto J. Strasser - Can we predict winter survival in plants using chlorophyll a fluorescence?

“…This method is also suitable for continuous real-time in-situ monitoring. JIP-test parameters gave much information on plant performance when applied in field conditions in agriculture and horticulture (Tsonev et al 2011, Swoczyna et al 2019, forestry (Pollastrini et al 2014, Bussotti andPollastrini 2015), urban environment (Hermans et al 2003, Ugolini et al 2012, Swoczyna et al 2015, ecological research (Bąba et al 2016), etc.…”

Special issue in honour of Prof. Reto J. Strasser - Structural and functional response of photosynthetic apparatus of radish plants to iron deficiency

“…The changes in fluorescence signals are related, directly or indirectly, to various stages of photosynthetic light reactions: photolysis of water, reduction of photosynthetic machinery components, electron transport, generation of the pH gradient across thylakoid membranes, and ATP synthesis (Goltsev et al 2016, Kalaji et al 2017a. The technique based on detailed analysis of Chl a fluorescence signals is known as JIP-test (Strasser et al 2004), which is frequently used to study the changes in structure and function of photosynthetic apparatus (Kautsky and Hirsch 1931, Stirbet and Govindjee 2011, Kalaji et al 2014aChen et al 2015, Bąba et al 2016, Kalaji et al 2017a. Illumination of dark-adapted leaf tissue leads to an increase of a prompt Chl fluorescence (PF) signal, which curves are named as chlorophyll fluorescence induction curves.…”