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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
411
pubmed:dateCreated
2005-1-27
pubmed:abstractText
Rice (Oryza sativa L.) has been used to study the long-term responses of photosynthesis to high irradiance focusing on the composition of the photosynthetic apparatus and leaf morphology. Typical sun/shade differences in chloroplast composition are seen in the fifth leaf following growth in high irradiance compared with low irradiance (1000 and 200 micromol m(-2) s(-1), respectively): higher light-saturated rates of photosynthesis (P(max)), higher amounts of Rubisco protein, and a lower chlorophyll a:b ratio. In addition, leaves were thicker under high light compared with low light. However, responses appear more complex when leaf developmental stage is considered. Using a system of transferring plants from low to high light in the laboratory responses that occur before and after full leaf extension have been studied. Acclimation of photosynthesis is limited by leaf age: the transfer to high light, post-leaf extension, is characterized by alterations in chlorophyll a:b but not in Rubisco protein, which may be limited by leaf morphology. Microarray analysis of gene expression was carried out on plants that were transferred to high light post-leaf extension. A down-regulation of light-harvesting genes was seen. No change in the expression level of Rubisco genes was observed. Up-regulation of genes involved in photoprotection was observed. It was also shown that high-light leaf morphology is established prior to formation of the zone of cellular elongation and division. The endogenous and environmental factors which establish the characteristics of high light acclimation may be important for attaining high rates of assimilation in leaves and crop canopies, and the fifth leaf in rice provides a convenient model system for the determination of the mechanisms involved.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0022-0957
pubmed:author
pubmed:issnType
Print
pubmed:volume
56
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
449-60
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Acclimation of photosynthesis to high irradiance in rice: gene expression and interactions with leaf development.
pubmed:affiliation
Department of Molecular Biology and Biotechnology, Firth Court, Western Bank, University of Sheffield, Sheffield S10 2TN, UK. e.h.murchie@sheffield.ac.uk
pubmed:publicationType
Journal Article