Effects of heat stress on photosystem II activity and antioxidant enzymes in two maize cultivars

Main conclusion The main reason for the maize genotype “DKC7221” to be heat tolerant is to have higher photosynthetic activity under heat stress conditions. The genotype “P3167” is sensitive to high temperature because of the heat-induced inhibition in photosynthetic electron transport reactions. In...

Full description

Saved in:
Bibliographic Details
Published in:Planta 2021-04, Vol.253 (4), p.85-85, Article 85
Main Author: Doğru, Ali
Format: Article
Language:English
Subjects:
Accumulation
Agriculture
Antioxidants
Ascorbic acid
Biomedical and Life Sciences
Chlorophyll
Corn
Cultivars
Ecology
Efficiency
Electron transport
Enzymes
Fluorescence
Forestry
Genotype & phenotype
Genotypes
Heat resistance
Heat stress
Heat tolerance
Heat-Shock Response
High temperature
Hydrogen Peroxide
Life Sciences
Malondialdehyde
Original Article
Oxidative stress
Photochemicals
Photosynthesis
Photosystem II
Photosystem II Protein Complex - metabolism
Physiological effects
Pigments
Plant Leaves - metabolism
Plant Sciences
Plant tissues
Proline
Reaction centers
Stress, Physiological
Superoxide
Zea mays
Zea mays - metabolism
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Main conclusion The main reason for the maize genotype “DKC7221” to be heat tolerant is to have higher photosynthetic activity under heat stress conditions. The genotype “P3167” is sensitive to high temperature because of the heat-induced inhibition in photosynthetic electron transport reactions. In the present study, the effect of heat stress (45 ºC for 20 min) on some physiological changes was investigated through a chlorophyll afluorescence technique, and some endogenous resistance mechanisms (activities of some antioxidant enzymes, free proline, and reduced ascorbate contents) in two maize cultivars ( Zea mays L. cvs. P3167 and DKC7221). Chlorophyll fluorescence measurements demonstrated that heat stress led to the reduction in the efficiency of the Hill reaction, accumulation of inactive reaction centers, inhibition of electron flow from reaction centers to the plastoquinone pool, and induction of non-photochemical dissipation of absorbed light energy. Changes in Φo/(1 – Φo), SFI ABS and PI ABS indicated that electron transport reactions in P3167 were almost completely inhibited by heat stress. In DKC7221, however, photosynthetic electron transport reactions were maintained under heat stress conditions. As a result of impairment in the photosynthetic efficiency in P3167 under heat stress, oxidative stress appeared as shown by lower antioxidant activity, accumulation of H 2 O 2 , malondialdehyde, and formazon and photooxidative injuries in chlorophyll pigments in the leaf tissue. DKC7221, on the other hand, had a higher antioxidant efficiency and lower oxidative damage under heat stress. FeSOD activity was found to be responsible for the dismutation of superoxide radicals in both maize genotypes under heat stress. As a result, it may be concluded that the genotype DKC7221 is more tolerant to heat stress than P3167.
ISSN:0032-0935
1432-2048
DOI:10.1007/s00425-021-03611-6