Glycinebetaine enhances the tolerance of tomato plants to high temperature during germination of seeds and growth of seedlings

Abstract

Tomato (Lycopersicon esculentum cv. 'Moneymaker') was transformed with a codA gene, from Arthrobacter globiformis, for choline oxidase that had been modified to allow targeting to both chloroplasts and the cytosol. Glycinebetaine (GB) accumulated in seeds of transformed plants up to 1 mmol g -1 dry weight (DW), while no detectable GB was found in wild-type (WT) seeds. The codA-transgenic seeds germinated faster and at higher frequency than WT seeds with high temperature treatment. After heat stress, levels of expression of a mitochondrial small heat-shock protein (MT-sHSP), heat-shock protein 70 (HSP70) and heat-shock cognate 70 (HSC70) were higher in transgenic seeds than in WT seeds during heat stress, and the accumulation of HSP70 was more prominent in codA-transgenic seeds than in WT seeds. Addition of GB to the germination medium or imbibition of seeds in a solution of GB enhanced the tolerance of WT seeds to high temperatures. WT seeds treated with exogenous GB also expressed heat-shock genes at elevated levels and accumulated more HSP70 than controls. Our results suggest that GB, either applied exogenously or accumulated in vivo in codA-transgenic seeds, enhanced the expression of heat-shock genes in and improved the tolerance to high temperature of tomato seeds during germination.

Analysis of transcriptional response to heat stress in Rhazya stricta

“…We confirmed these results for genes encoding WRKY6, WRKY7, WRKY12, WRKY33, WRKY40, WRKY44, WRKY46, WRKY48, WRKY49, WRKY50, WRKY53 and WRKY55 (Additional file 2: Table S2 & Additional file 6: Table S3). There are reports indicating that the constitutive expression of genes encoding WRKY25, WRKY26 or WRKY33 enhanced tolerance to heat stress [101]. No previous reports have indicated the direct involvement of WRKY in driving hsp genes, including the shsp20 .…”

ABA-INSENSITIVE3, ABA-INSENSITIVE5, and DELLAs Interact to Activate the Expression ofSOMNUSand Other High-Temperature-Inducible Genes in Imbibed Seeds inArabidopsis

“…Other plant hormones, including ethylene, cytokinin, and strigolactone, also promote seed germination at high temperature (Khan and Prusinski, 1989;Matilla, 2000;Kozarewa et al, 2006;Toh et al, 2012). In addition, a number of genetic components (e.g., TRANSPARENT TESTA7, pea [Pisum sativum] G-protein a-and b-subunits, chickpea [Cicer arietinum] APETALA2 [AP2], and wheat [Triticum aestivum] chloroplastic small heat shock proteins) and various chemicals (e.g., CO 2 , 2-4-[carboxyphenyl]-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, chlorogenic acid, bovine hemoglobin, isoprene, and glycinebetaine) affect seed germination at high temperature (Saini et al, 1986;Tamura et al, 2006;Misra et al, 2007;Shukla et al, 2009;Hossain et al, 2010;Li et al, 2011;Chauhan et al, 2012). However, the relationships among these components have not yet been clarified.…”

Foliar Application of Glycine Betaine Mitigates the Effect of Heat Stress in Three Marigold (<i>Tagetes erecta</i>) Cultivars

“…The exogenous application of GB is a safe and simple method that has been successfully used to improve heat stress tolerance in tomato (Li et al, 2011;Makela et al, 1998) and sugarcane (Rasheed et al, 2011). In this study, the results show that foliar application of GB can effectively mitigate the effect of heat stress in 3 marigold cultivars.…”