Alterations in photochemical efficiency of photosystem II in wheat plant on hot summer day

Mathur, Sonal; Jajoo, Anjana

doi:10.1007/s12298-014-0249-z

Cited by 32 publications

(20 citation statements)

References 25 publications

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“…We hypothesized that photosynthesis and pollen viability under heat treatment are negatively impacted. Although changes in photosystem‐II efficiency have been associated with grain yield (Ort et al , ; Sanchez‐Bragado et al , ; Lin et al , ), as well as with responses to heat (Mathur and Jajoo, ; Yamamoto, ), we did not find statistically significant evidence that photosystem‐II efficiency was affected by heat. Similarly, we did not find statistically significant changes in pollen viability, despite pollen viability having been reported to be affected by heat in other species (Schoper et al , ; Vara Prasad et al , ; Kumar et al , ; Jiang et al , ), as well as in quinoa (Hinojosa, Matanguihan, et al , ).…”

Section: Resultscontrasting

confidence: 82%

Heating quinoa shoots results in yield loss by inhibiting fruit production and delaying maturity

et al. 2020

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Increasing global temperatures and a growing world population create the need to develop crop varieties that provide higher yields in warmer climates. There is growing interest in expanding quinoa cultivation, because of the ability of quinoa to produce nutritious grain in poor soils, with little water and at high salinity. The main limitation to expanding quinoa cultivation, however, is the susceptibility of quinoa to temperatures above approximately 32°C. This study investigates the phenotypes, genes and mechanisms that may affect quinoa seed yield at high temperatures. Using a differential heating system where only roots or only shoots were heated, quinoa yield losses were attributed to shoot heating. Plants with heated shoots lost 60-85% yield as compared with control plants. Yield losses were the result of lower fruit production, which lowered the number of seeds produced per plant. Furthermore, plants with heated shoots had delayed maturity and greater non-reproductive shoot biomass, whereas plants with both heated roots and heated shoots produced higher yields from the panicles that had escaped the heat, compared with the control. This suggests that quinoa uses a type of avoidance strategy to survive heat. Gene expression analysis identified transcription factors differentially expressed in plants with heated shoots and low yield that had been previously associated with flower development and flower opening. Interestingly, in plants with heated shoots, flowers stayed closed during the day while the control flowers were open. Although a closed flower may protect the floral structures, this could also cause yield losses by limiting pollen dispersal, which is necessary to produce fruit in the mostly female flowers of quinoa.

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Section: Resultscontrasting

confidence: 82%

Heating quinoa shoots results in yield loss by inhibiting fruit production and delaying maturity

et al. 2020

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“…The disappearance of the K step after 72 h may indicate restoration of OEC function, which we attribute to prior acclimation of C. saccharophila to environmental factors to which it was exposed. Similar observation has been reported by Mathur and Jajoo () in wheat plants, where the K step appeared upon increased day temperature, but was diminished with time after continuous exposure of plants to sunlight. The thermostability of OEC in high temperature stress plants has been reported previously by Wang et al .…”

Section: Resultssupporting

confidence: 90%

Photosynthetic acclimation of Chlorella saccharophila to heat stress

Patil

Pandit

Lali

2017

Phycological Research

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Photosynthesis is one of the most important metabolic processes of algae; which is altered as a stress response. During mass cultivation of algae, temperature rise and high light are major factors that affect biomass productivity. High temperature affects photosystem II (PSII) complex irreversibly, damaging intermolecular interactions in it. However, the impact of high temperature on photosynthesis is highly variable among different algal species, depending on the prior acclimation to environmental conditions they were exposed to. The acclimation plays an important role in combating high temperature stress via regulation of photosynthetic responses. Chlorophyll a fluorescence is a highly sensitive, non-destructive and reliable tool for such measurements of photosynthetic parameters, which provides information about algal photosynthetic performance under given conditions. To understand the effect of heat stress on the responses of high light acclimated alga Chlorella saccharophila, chlorophyll a fluorescence transients were measured after heat exposure at 40 C. Our study demonstrates that rise in temperature for short duration; during open field cultivation reversibly affects the efficiency of PSII in light acclimated alga C. saccharophila. The effects of heat stress on chlorophyll a fluorescence in this alga, grown under high light (max-1600 μmol photons m −2 s −1 ) are presented here; they are used to infer changes in photosynthetic process during its exposure to heat, as well as their recovery after 72 h. We speculate that heat resistance may have been acquired due to prior exposures to high light.

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“…It has been shown that salt stress reduces photosynthetic activities in plants via the inhibition of photosystem II complex (PSII) at both acceptor [QA] and donor sides (oxygen-evolving complex OEC), and destruction of chlorophyll pigments by the accumulation of toxic ions (Chen and Murata 2011; Shu et al 2012). The reduction observed in F v /F m may be associated with damage to the PSII reaction center (Kadir et al 2007) and the decrease in the quantum efficiency of PSII photochemistry (Mathur and Jajoo 2014). The dissipation energy ( DIo / RC ) and electron flux ( ETo/RC ) per active reaction center increased during salt stress, due to the increased proportion of the inactive reaction centers in the leaves exposed to salt stress (Mehta et al 2011), resulting in the ineffective exploitation of light energy received in the inactivated reaction centers (Satoh et al 1983).…”

Section: Discussionmentioning

confidence: 99%

Genetic and transcriptional variations in NRAMP-2 and OPAQUE1 genes are associated with salt stress response in wheat

Oyiga

Ogbonnaya

Sharma³

et al. 2018

Theor Appl Genet

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Key messageSNP alleles on chromosomes 4BL and 6AL are associated with sensitivity to salt tolerance in wheat and upon validation can be exploited in the development of salt-tolerant wheat varieties.AbstractThe dissection of the genetic and molecular components of salt stress response offers strong opportunities toward understanding and improving salt tolerance in crops. In this study, GWAS was employed to identify a total of 106 SNP loci (R2 = 0.12–63.44%) linked to salt stress response in wheat using leaf chlorophyll fluorescence, grain quality and shoot ionic (Na+ and K+ ions) attributes. Among them, 14 SNP loci individually conferred pleiotropic effects on multiple independent salinity tolerance traits including loci at 99.04 cM (R2 ≥ 14.7%) and 68.45 cM (R2 ≥ 4.10%) on chromosomes 6AL and 4BL, respectively, that influenced shoot Na+-uptake, shoot K+/Na+ ratio, and specific energy fluxes for absorption (ABS/RC) and dissipation (DIo/RC). Analysis of the open reading frame (ORF) containing the SNP markers revealed that they are orthologous to genes involved in photosynthesis and plant stress (salt) response. Further transcript abundance and qRT-PCR analyses indicated that the genes are mostly up-regulated in salt-tolerant and down-regulated in salt-sensitive wheat genotypes including NRAMP-2 and OPAQUE1 genes on 4BL and 6AL, respectively. Both genes showed highest differential expression between contrasting genotypes when expressions of all the genes within their genetic intervals were analyzed. Possible cis-acting regulatory elements and coding sequence variation that may be involved in salt stress response were also identified in both genes. This study identified genetic and molecular components of salt stress response that are associated with Na+-uptake, shoot Na+/K+ ratio, ABS/RC, DIo/RC, and grain quality traits and upon functional validation would facilitate the development of gene-specific markers that could be deployed to improve salinity tolerance in wheat.Electronic supplementary materialThe online version of this article (10.1007/s00122-018-3220-5) contains supplementary material, which is available to authorized users.

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Alterations in photochemical efficiency of photosystem II in wheat plant on hot summer day

Cited by 32 publications

References 25 publications

Heating quinoa shoots results in yield loss by inhibiting fruit production and delaying maturity

Heating quinoa shoots results in yield loss by inhibiting fruit production and delaying maturity

Photosynthetic acclimation of Chlorella saccharophila to heat stress

Genetic and transcriptional variations in NRAMP-2 and OPAQUE1 genes are associated with salt stress response in wheat

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