Overexpression of a tomato flavanone 3-hydroxylase-like protein gene improves chilling tolerance in tobacco.

Flavonoids are secondary metabolites found in plants with a wide range of biological functions, such as stress protection. This study investigated the functions of a tomato (Solanum lycopersicum) flavanone 3-hydroxylase-like protein gene SlF3HL by using transgenic tobacco. The expression of the gene was up-regulated under chilling (4 °C), heat (42 °C), salt (NaCl) and oxidative (H2O2) stresses.

Heterology expression of the tomato LeLhcb2 gene confers elevated tolerance to chilling stress in transgenic tobacco.

Chilling is one of the most serious environmental stresses that disrupt the metabolic balance of cells and enhance the production of reactive oxygen species (ROS). Light harvesting complex (LHC) proteins had a function in dissipating excess excitation energy and eliminating ROS to maintain the normal physiological function of cells. A tomato (Lycopersicon esculentum) LHC antenna protein gene (LeLhcb2) was isolated.

Overexpression of a tomato carotenoid ε-hydroxylase gene alleviates sensitivity to chilling stress in transgenic tobacco.

Chilling is one of the most serious environmental stresses that disrupt the metabolic balance of cells and enhance the production of reactive oxygen species (ROS). Lutein plays important roles in dissipating excess excitation energy and eliminating ROS to maintain the normal physiological function of cells. A tomato carotenoid epsilon-ring hydroxylase gene (LeLUT1) was isolated, and the LeLUT1-GFP fusion protein was localized in the chloroplast of Arabidopsis mesophyll protoplast.

Antisense-mediated depletion of tomato GDP-L-galactose phosphorylase increases susceptibility to chilling stress.

The GDP-L-galactose phosphorylase (GGP), which converts GDP-l-galactose to l-Gal-1-phosphate, is generally considered to be a key enzyme of the major ascorbate biosynthesis pathways in higher plants, but experimental evidence for its role in tomato is lacking. In the present study, the GGP gene was isolated from tomato (Solanum lycopersicum) and transient expression of SlGGP-GFP (green fluorescent protein) fusion protein in onion cells revealed the cytoplasmic and nucleus localization of the protein. Antisense transgenic tomato lines with only 50-75% ascorbate level of the wild type (WT) were obtained.

Antisense-mediated suppression of tomato thylakoidal ascorbate peroxidase influences anti-oxidant network during chilling stress.

Photosynthesis is a well-established source of reactive oxygen species (ROS) in plants particularly under chilling stress. Ascorbate peroxidase (APXs) plays an important role in the anti-oxidant system by utilizing AsA as specific electron donor to reduce H(2)O(2) to water. In order to investigate the possible mechanisms of ascorbate peroxidsae (APX) in photoprotection under chilling stress, a tomato (Lycopersicon esculentum Mill.

Constitutive accumulation of zeaxanthin in tomato alleviates salt stress-induced photoinhibition and photooxidation.

Zeaxanthin (Z) has a role in the dissipation of excess excitation energy by participating in non-photochemical quenching (NPQ) and is essential in protecting the chloroplast from photooxidative damage. To investigate the physiological effects and functional mechanism of constitutive accumulation of Z in the tomato at salt stress-induced photoinhibition and photooxidation, antisense-mediated suppression of zeaxanthin epoxidase transgenic plants and the wild-type (WT) tomato were used. The ratio of Z/(V + A + Z) and (Z + 0.

Antisense-mediated depletion of tomato chloroplast glutathione reductase enhances susceptibility to chilling stress.

A tomato (Lycopersicon esculentum Mill.) chloroplast glutathione reductase gene (LeGR) was isolated and antisense transgenic tomato lines were obtained. Under chilling stress, transgenic plants accumulated more H(2)O(2), leaked more electrolyte and showed lower net photosynthetic rate (Pn), maximal photochemical efficiency of PSII (Fv/Fm) and oxidizable P700 compared with wild-type (WT) plants.