Phosphoinositide-specific phospholipase C gene involved in heat and drought tolerance in wheat (Triticum aestivum L.).

BACKGROUND: Phosphoinositide-specific phospholipase C proteins mediate environmental stress responses in many plants. However, the potential of PI-PLC genes involved with abiotic stress tolerance in wheat remains un-explored. OBJECTIVE: To study TaPLC1 genetic relation with wheat drought and heat resistance. METHODS: The seedlings were treated with PI-PLC inhibitor U73122 at the single leaf stage. The seedlings were treated with drought and heat stress at the two leaf stage, and some physiological indexes and the expression profile of TaPLC1 gene were determined. And the TaPLC1 overexpression vector was transferred to Arabidopsis and selected to T3 generation for drought and heat stress treatment. RESULTS: After 4 h of drought and heat stress, the SOD activity, MDA and soluble sugar content of the two cultivars with inhibitor were higher than those without inhibitor, the chlorophyll content decreased. CS seedlings showed significant wilting phenomenon, and TAM107 showed slight wilting. After the elimination of drought and heat stress, all seedling wilting gradually recovered, while the leaf tips of the two varieties treated with inhibitors began to wilt and turn yellow, which was more significant 5 days after the drought and heat stress, while the degree of spring wilting and yellow in CS was earlier than that in TAM107. The expression patterns of TaPLC1 gene were different in the two cultivars, but the expression levels reached the maximum at 30 min of heat stress. The change of TaPLC1 expression in TAM107 without inhibitor treatment was significantly greater than that in CS. The expression level of TaPLC1 in the two cultivars under stress was significantly different between the two cultivars treated with inhibitor and untreated, and was lower than that of the normal plants under normal conditions. These results indicated that inhibition of TaPLC1 gene expression could enhance the sensitivity of seedlings to stress. In Arabidopsis, the root lengths of transgenic and wild-type seedlings were shortened after drought stress treatment, but the root lengths of transgenic plants decreased slightly. And the expression of TaPLC1 gene was significantly increased after drought and heat stress. This indicated that overexpression of TaPLC1 improved drought resistance of Arabidopsis. CONCLUSIONS: The results of this study suggest that TaPLC1 may be involved in the regulation mechanism of drought and heat stress in wheat.

[EFFECTS OF BONE MARROW MESENCHYMAL STEM CELLS TRANSPLANTATION FOR TREATING RAT SPINAL CORD INJURY AND CYTOKINE EXPRESSION AT INJURY SITES].

OBJECTIVE: To investigate the effects of bone marrow mesenchymal stem cells (BMSCs) transplantation for treating spinal cord injury (SCI) in rat and the cytokine expression changes in the local injury tissues. METHODS: BMSCs were separated from Sprague Dawley (SD) rat and cultured with the whole bone marrow culture method. rAd-EGFP was used to transfect the 5th generation BMSCs for green fluorescent protein (GFP) label. Twelve SD rats were randomly divided into experimental group (n = 6) and control group (n = 6). After the T10 SCI model was established with Allen's impact device in 2 groups, 1 x 1096) GFP-labeled BMSCs and PBS were administered by subarachnoid injection in situ in experimental group and control group, respectively. Basso-Beattie-Bresnahan (BBB) score was used to detect the motor function at immediat, 1, 2, 3, 4, and 5 weeks after SCI. At 5 weeks, the spinal cord tissues were harvested for the histological and immunofluorescent staining examinations to measure the expressions of neural marker molecules, including Nestin, glial fibrillary acidic protein (GFAP), and neuron-specific nuclear protein (NeuN). Cytokine was analyzed with antibody array. RESULTS: At 5 weeks, 2 rats died of urinary tract infection in 2 groups respectively, the other rats survived to the end of experiment. BBB score of experimental group was significantly higher than that of control group at 1, 2, 3, 4, and 5 weeks (P < 0.05). At 5 weeks, histological results showed that there were many cells with regular arrangement in the experimental group; there were less cells with irregular arrangement in the control group. Compared with the control group, Nestin and NeuN expressions significantly increased (P < 0.05), and GFAP expression significantly decreased (P < 0.05) in the experimental group. Leptin and ciliary neurotrophic factor levels were higher in the experimental group than the control group, but granulocyte-macrophage colony-stimulating factor, tumor necrosis factor ß, interleukin 1 ß, and tissue inhibitor of metalloproteinases 1 levels were lower in the experimental group than the control group. CONCLUSION: BMSCs transplantation can improve survival and regeneration of nerve cells and enhances the recovery of nerve function by regulating secretion of cytokines from grafted BMSCs.