In vitro selection of salinity tolerant variants from triploid bermudagrass (Cynodon transvaalensis × C. dactylon) and their physiological responses to salt and drought stress

Abstract

A protocol was established for in vitro selection of salinity tolerant somaclonal variations from suspension cultured calli of triploid bermudagrass cv. TifEagle. To induce somaclonal variations the calli were subcultured for 18 months and were then subject to three-round selections for salt-tolerant calli by placing on solid medium containing 0.3 M NaCl for 10 days followed by a recovery for 2 weeks. The surviving calli were regenerated on regeneration medium containing 0.1 M NaCl. Three somaclonal variant lines (2, 71, and 77) were obtained and analyzed. The selected somaclonal lines showed higher relative growth and less injury than TifEagle under salt stress, indicating that they increased salt tolerance. In addition, they had higher relative water content and lower electrolyte leakage than TifEagle after withholding irrigation, indicating that they also increased drought tolerance. The three somaclonal variant lines had higher proline content than TifEagle under normal growth condition. The line 71 had a higher K(+)/Na(+) ratio, whereas the lines 2 and 77 had higher CAT activity under control and salt stress conditions, indicating that different mechanisms for salt tolerance might exist in these three lines.

Oxidative Stress Studies in Plant Tissue Culture

“…In plants screening for variations depending on the ability to tolerate relatively high levels of stressors in media, various systems, such as callus, cell suspensions, embryonic callus, shoot cultures, nodal cultures, have been used in tissue culture conditions. It is assumed that in vitro selection is an efficient, a rapid and a low cost breeding method (Lu et al, 2007;Rai et …”

Improved abiotic stress tolerance of bermudagrass by exogenous small molecules

“…Analysis of natural variations of drought stress tolerance revealed that different bermudagrass cultivars exhibited varied tolerance to drought stress. [1][2][3] Exogenous application of small molecules could effectively alleviate damages caused by multiple abiotic stresses, including drought, salt and cold. [4][5][6][7][8] Exogenous ABA treatment improved drought stress tolerance in 'TifEagle' cultivar through induction of H 2 O 2 and NO, which, in turn, enhanced antioxidant enzyme activities.…”

“…9 Further studies showed that abiotic stress treatments changed antioxidant enzyme activities, ROS contents, osmoprotectant contents (sugar, sucrose, dehydrin, proline), and photosynthesis. [1][2][5][6][10][11][12][13][14] Recently, proteomics and metabolomics approaches have been successfully used to detect omic level changes during bermudagrass stress responses. Under water-deficit condition, 32 proteins had increases in the abundance and 22 proteins exhibited decreases in the abundance, which were mainly involved in metabolism, energy, cell growth/division, protein synthesis and stress defense.…”

In Vitro Analysis of Taurine as Anti-stress Agent in Tomato (Solanum Lycopersicum)-Preliminary Study

“…This study utilized plant tissue culture protocols that circumvent the potential problems in taurine transport. In addition, plant tissue culture is important for devising an effi cient protocol for callus proliferation to start in vitro selection for various stress tolerance, and to expand the opportunities for genetic manipulation of useful plants through tissue culture using various explants and media (Jha and Ghosha 2005 ;Hossain et al 2007 ;Lu et al 2007 ). Tissue culture serves as a useful tool for characterizing the effect of a biochemical substance on plants by a direct application.…”