Overexpression of zeaxanthin epoxidase gene enhances the sensitivity of tomato PSII photoinhibition to high light and chilling stress.
A tomato (Lycopersicon esculentum Mill.) zeaxanthin epoxidase gene (LeZE) was isolated. The deduced amino acid sequence of LeZE showed high identities with zeaxanthin epoxidase in other plant species. Northern blot analysis showed that the mRNA accumulation of LeZE in the wild-type (WT) was not induced by light and temperature but regulated by the diurnal rhythm. The sense transgenic plants were obtained under the control of the cauliflower mosaic virus 35S promoter (35S-CaMV). Northern and western blot analysis confirmed that sense LeZE was transferred into the tomato genome and overexpressed. The ratio of (A + Z)/(V + A + Z) and the values of non-photochemical quenching were lower in transgenic plants than in WT plants under high light and chilling stress with low irradiance. The O(2) evolution rate and the maximal photochemical efficiency of PSII (Fv/Fm) in transgenic plants decreased more quickly during both stresses and recovered slower than that in WT under optimal conditions. These results suggested that overexpression of LeZE impaired the function of the xanthophyll cycle and aggravated PSII photoinhibition in tomato under high light and chilling stress.
Wang
Ning
N
College of Life Science, State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an 271018, China.
Fang
Wei
W
Han
Han
H
Sui
Na
N
Li
Bin
B
Meng
Qing-Wei
QW
D001483:Base Sequence; D003080:Cold Temperature; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D015870:Gene Expression; D017343:Genes, Plant; D008027:Light; D018551:Solanum lycopersicum / Q000201:enzymology* / Q000235:genetics* / Q000528:radiation effects; D010088:Oxidoreductases / Q000235:genetics*; D045332:Photosystem II Protein Complex / Q000528:radiation effects; D030821:Plants, Genetically Modified; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism
D017931:DNA Primers; D018076:DNA, Complementary; D018744:DNA, Plant; D045332:Photosystem II Protein Complex; D018749:RNA, Plant; D010088:Oxidoreductases; C097153:zeaxanthin epoxidase