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Chlorophyll-depleted wheat mutants are disturbed in photosynthetic electron flow regulation but can retain an acclimation ability to a fluctuating light regime
- Source :
- Environmental and Experimental Botany
-
Abstract
- The search for more productive crops is exploring accessions with reduced chlorophyll accumulation in leaves, which would promote plant growth mainly because of a higher light transmittance throughout the canopy. Under continuous light, chlorophyll-depleted chlorina mutants of wheat can reach yields similar to WT; however, their performance under fluctuating light could possibly be lowered by a disturbed photosynthetic electron transport. Six chlorina mutants of Triticum aestivum (ANBW4A, ANBW4B, ANK32A) or T. durum (ANDW7A, ANDW7B, ANDW8A) were compared to WT genotypes under continuous and fluctuating light regimes, the latter obtained through a randomized pattern of light intensity changes. After two weeks of plant acclimation under either regimes, light energy management was thoroughly analysed for four weeks. All chlorina mutants showed a defective ability to regulate the electron poise during a fast rise in irradiance. Different extent of deregulation depended on mutation and genomic background, durum wheat being more severely impaired than bread wheat. However, a great acclimative capacity to a fluctuating light regime unexpectedly still characterized the chlorina wheat plants, with the only exception of the mutants carrying the cn-B1b mutated locus (ANDW7B and ANBW4B). Under fluctuating light, all other chlorina mutants developed indeed an ability to improve their control of electron transport against the recurrent reducing bursts caused by lightflecks. Compensatory responses included the regulation of energy distribution between photosystems, the use of alternative electron sinks, and a structural reorganization of the thylakoid system. However, in no case a reduced chlorophyll content led to more productive plants. Among 23 measured photosynthetic parameters, especially the non-regulatory energy dissipation in photosystem II - Y(NO) –, when probed during a light rise, can be proposed in automated phenotyping experiments as a straightforward index to be used for chlorina wheat screening with respect to potential productivity.
- Subjects :
- 0106 biological sciences
0301 basic medicine
Photosystem II
Photosynthetic acclimation
Plant Science
Photosynthesis
01 natural sciences
Acclimatization
chlorina mutant
03 medical and health sciences
chemistry.chemical_compound
Photosynthetic electron transport
LS1_8
LS9_5
Ecology, Evolution, Behavior and Systematics
Photosystem
2. Zero hunger
food and beverages
Ambientale
Electron transport chain
Fluctuating light
Light intensity
Horticulture
030104 developmental biology
chemistry
Chlorophyll
Thylakoid
Wheat
Agronomy and Crop Science
010606 plant biology & botany
Subjects
Details
- Language :
- English
- ISSN :
- 00988472
- Volume :
- 178
- Database :
- OpenAIRE
- Journal :
- Environmental and Experimental Botany
- Accession number :
- edsair.doi.dedup.....3e2a6b80fe348196219b5511f3612615
- Full Text :
- https://doi.org/10.1016/j.envexpbot.2020.104156