title: Analysis of elevated temperature-induced inhibition of photosystem II using chlorophyll a fluorescence induction kinetics in wheat leaves (Triticum aestivum).
abstract: Wheat is the major crop plant in many parts of the world. Elevated temperature-induced changes in photosynthetic efficiency were studied in wheat (T. aestivum) leaves by measuring Chl a fluorescence induction kinetics. Detached leaves were subjected to elevated temperature stress of 35 °C, 40 °C or 45 °C. Parameters such as Fv/Fm, performance index (PI), and reaction centre to absorbance ratio (RC/ABS) were deduced using radial plots from fluorescence induction curves obtained with a plant efficiency analyser (PEA). To derive precise information on fluorescence induction kinetics, energy pipeline leaf models were plotted using biolyzer hp3 software. At 35 °C, there was no effect on photosynthetic efficiency, including the oxygen-evolving complex, and the donor side of PSII remained active. At 40 °C, activity was reduced by 14%, while at 45 °C, a K intermediate step was observed, indicating irreversible damage to the oxygen-evolving complex. This analysis can be used to rapidly screen for vitality and stress tolerance characteristics of wheat growing in the field under high temperature stress.
authors.affiliation: School of Life Science, Devi Ahilya University, Indore, MP, India.
authors.forename: S
authors.initials: S
authors.lastname: Mathur
authors.forename: A
authors.initials: A
authors.lastname: Jajoo
authors.forename: P
authors.initials: P
authors.lastname: Mehta
authors.forename: S
authors.initials: S
authors.lastname: Bharti
mesh_terms: D002734:Chlorophyll / Q000032:analysis* / Q000378:metabolism; D000077194:Chlorophyll A; D007700:Kinetics; D045332:Photosystem II Protein Complex / Q000378:metabolism*; D018515:Plant Leaves / Q000737:chemistry / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D013696:Temperature; D014908:Triticum / Q000737:chemistry / Q000378:metabolism*
chemical_list: D045332:Photosystem II Protein Complex; D002734:Chlorophyll; D000077194:Chlorophyll A