Overexpression of endoplasmic reticulum omega-3 fatty acid desaturase gene improves chilling tolerance in tomato.
An endoplasmic reticulum-localized tomato omega-3 fatty acid desaturase gene (LeFAD3) was isolated and characterized with regard to its sequence, response to various temperatures and function in transgenic tomato plants. Northern blot analysis showed that LeFAD3 was expressed in all organs tested and was markedly abundant in roots. Meanwhile, the expression of LeFAD3 was induced by chilling stress (4 degrees C), but inhibited by high temperature (40 degrees C). The transgenic plants were obtained under the control of the cauliflower mosaic virus 35S promoter (35S-CaMV). Northern and western blot analyses confirmed that sense LeFAD3 was transferred into tomato genome and overexpressed. Level of linolenic acids (18:3) increased and correspondingly level of linoleic acid (18:2) decreased in leaves and roots. After chilling stress, the fresh weight of the aerial parts of transgenic plants was higher than that of the wild type (WT) plants, and the membrane system ultrastructure of chloroplast in leaf cell and all the subcellular organelles in root tips of transgenic plants kept more intact than those of WT. Relative electric conductivity increased less in transgenic plants than that in WT, and the respiration rate of the transgenic plants was notably higher than that of WT. The maximal photochemical efficiency of PSII (F(v)/F(m)) and the O(2) evolution rate in WT decreased more than those in transgenic plants under chilling stress. Together with other data, results showed that the overexpression of LeFAD3 led to increased level of 18:3 and alleviated the injuries under chilling stress.
Yu
Chao
C
College of Life Science, State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an 271018, PR China.
Wang
Hua-Sen
HS
Yang
Sha
S
Tang
Xian-Feng
XF
Duan
Ming
M
Meng
Qing-Wei
QW
D000222:Adaptation, Physiological / Q000235:genetics*; D018533:Biomass; D015152:Blotting, Northern; D015153:Blotting, Western; D017796:Caulimovirus; D019069:Cell Respiration; D002736:Chloroplasts / Q000648:ultrastructure; D003080:Cold Temperature; D004553:Electric Conductivity; D004721:Endoplasmic Reticulum / Q000201:enzymology* / Q000235:genetics; D044943:Fatty Acid Desaturases / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D017343:Genes, Plant; D007425:Intracellular Membranes / Q000648:ultrastructure; D019787:Linoleic Acid / Q000378:metabolism; D008042:Linolenic Acids / Q000378:metabolism; D018551:Solanum lycopersicum / Q000201:enzymology* / Q000235:genetics; D015388:Organelles / Q000648:ultrastructure; D010100:Oxygen / Q000378:metabolism; D045332:Photosystem II Protein Complex; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018514:Plant Structures / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D016415:Sequence Alignment; D013312:Stress, Physiological
D008042:Linolenic Acids; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D019787:Linoleic Acid; D044943:Fatty Acid Desaturases; D010100:Oxygen