Introduction of the carrot HSP17.7 into potato (Solanum tuberosum L.) enhances cellular membrane stability and tuberization in vitro

Abstract

We have examined the ability of a carrot (Daucus carota L.) heat shock protein gene encoding HSP17.7 (DcHSP17.7) to confer enhanced heat tolerance to potato (Solanum tuberosum L.), a cool‐season crop. The DcHSP17.7 gene was fused to a 6XHistidine (His) tag to distinguish the engineered protein from endogenous potato proteins and was introduced into the potato cultivar ‘Désirée’ under the control of the cauliflower mosaic virus (CaMV) 35S promoter. Western analysis showed that engineered DcHSP17.7 was constitutively, but not abundantly, expressed in transgenic potato lines before heat stress. Leaves from multiple regenerated potato lines that contain the transgene exhibited significantly improved cellular membrane stability at high temperatures, compared with wild‐type and vector control plants. Transgenic potato lines also exhibited enhanced tuberization in vitro: under a condition of constant heat stress, at 29 °C, nodal sections of the transgenic lines produced larger and heavier microtubers at higher rates, compared to the wild type and vector controls. The dry weight and percentages of microtubers that were longer than 5 mm were up to three times higher in the transgenic lines. Our results suggest that constitutive expression of carrot HSP17.7 can enhance thermotolerance in transgenic potato plants. To our knowledge, this is the first study that shows that the thermotolerance of potato can be enhanced through gene transfer.

A Mutant Small Heat Shock Protein with Increased Thylakoid Association Provides an Elevated Resistance Against UV-B Damage in Synechocystis 6803

“…In line with this concept, recently the carrot sHsp Hsp17.7 was introduced into potato, which exhibited significantly improved cellular membrane stability at high temperatures as evidenced by electrolyte leakage (42). Our findings imply the potential to genetically engineer enhanced stress tolerance in important agronomic crop plants by introducing an Hsp gene encoding Hsps with well defined membrane-interacting features.…”

Effect of drought and heat stresses on plant growth and yield: a review

“…It is worth adding that expression of some heat shock proteins (eg HSPs 70) can be enhanced by abscisic acid (ABA) (Pareek et al, 1998). Expression of genes inducing HSPs can be an important mechanism of increasing stress tolerance (thermotolerance) through getting better photosynthesis and water and nutrient use efficiency (Camejo et al, 2005) and cellular membrane stability (Ahn and Zimmerman, 2006) or hydration of cellular structures (Wahid and Close, 2007).…”

Class I and II small heat-shock proteins protect protein translation factors during heat stress

“…However, only single alleles were tested, and no complementation experiments were performed. Further evidence for the stress-protective role of CI and CII sHSPs in plants has primarily involved constitutive expression or overexpression of a single sHSP in different plant species, including Arabidopsis, rice (Oryza sativa), maize (Zea mays), and carrot (Daucus carota), as well as others (Malik et al, 1999;Ahn and Zimmerman, 2006;Jiang et al, 2009;Sun et al, 2012;Zhou et al, 2012;Mu et al, 2013;Wang et al, 2015). A very restricted set of stress-resistant phenotypes has been reported for sHSP-overexpressing transgenic materials, and these studies have not provided mechanistic insight into sHSP function or distinguished differences between CI and CII sHSPs.…”