Expression of the Heat Shock Response in a Tomato Interspecific Hybrid Is Not Intermediate between the Two Parental Responses

Abstract

While it is apparent that the heat shock response is ubiquitous, variabilities in the nature of the heat shock response between closely related species have not been well characterized. The heat shock response of three genotypes of tomato, Lycopersicon esculentum, Lycopersicon pennellii, and the interspecific sexual hybrid was characterized. The two parental genotypes differed in the nature of the heat shock proteins synthesized; the speciesspecific heat shock proteins were identified following in vivo labeling of leaf tissue with [35S]methionine and cysteine. The duration of, and recovery from, heat shock varied between the two species: L. esculentum tissue recovered more rapidly and protein synthesis persisted longer during a heat shock than in the wild species, L. pennellii. Both species induced heat shock protein synthesis at 350C and synthesis was maximal at 37°C.The response of the Fl to heat shock was intermediate to the parental responses for duration of, and recovery from, heat shock. In other aspects, the response of the Fl to heat shock was not intermediate to the parental responses: the Fl induced only half of the L. esculentum specific heat shock proteins, and all of the L. pennellii specific heat shock proteins. A discussion of the inheritance of the regulation of the heat shock response is presented.The response of many organisms to elevated temperature has been characterized and described as the heat shock response (13). While it is apparent that the heat shock response is ubiquitous, variations in the nature of the heat shock response between closely related species have not been well characterized. The heat shock response in plants has been well characterized primarily in two crop plants, soybean (2,8,12) and corn (3, 4), and to a lesser extent in a few other systems (5,7,10,16,17,23). There have been reports on the heat shock response of a cell culture of a wild species of tomato, Lycopersicon peruvianum (19,20,27) sity, including tolerances to abiotic stresses (25). We have been investigating the cell genetics of tomato species, in particular of two species, Lycopersicon esculentum, the cultivated tomato, and Lycopersicon pennellii, a green-fruited, drought-tolerant, and water-use efficient species (18, 25). Sexual and somatic hybridization can produce interspecific hybrids between these two species (22,24). We investigated the heat shock response in these two sexually compatible species to determine the range of variation of expression in the heat shock response and the nature of the expression of the response in the hybrid genotype. The parameters of the heat shock response that were measured included: the mol wt and isoelectric point of the HSPs2 synthesized, the temperatures of induction and of maximal synthesis, the differences in duration of and recovery from the heat shock. All of these parameters were characterized in the interspecific Fl and compared with the parental responses. MATERIALS AND METHODS Plant Materials and Growth Conditions

Heat induced changes in protein expression profiles of Norway spruce (Picea abies) ecotypes from different elevations

“…In various species a gradual increase in the tem-perature or short periods of very high sublethal temperatures followed by a recovery period at normal growth temperature induce a state of acquired thermotolerance to temperatures otherwise lethal [1,2]. Small HSP (sHSP) predominate in the HSR of plants [3] and have often been correlated with speciesspecific or ecotype-specific thermotolerance [4][5][6].…”

Genetics of the resistance to hypoxia in postlarvae and juveniles of the Pacific white shrimp Penaeus (Litopenaeus) vannamei (Boone 1931)

“…Also, for the guppy Poecilia reticulata , a large heterosis value (42.2%) has been found for salinity tolerance (Nakadate, Shikano & Taniguchi 2003), a trait also known to present significant inbreeding depression (Shikano, Chiyokubo & Taniguchi 2001), and for which directional dominance has been suggested to affect it (Shikano et al 2001). Dominant inheritance of the stress response has been also observed in inter‐specific hybrids of plants when measured as quantitative expression of HSPs, where it has been found that expression of some HSP types in the better‐surviving F1 occurs at a higher intensity for some of the HSP types derived from one of the parental contributors than the other (Fender & O'Connell 1990; Jorgensen & Nguyen 1995). In shrimp, whereas HSPs are known to be expressed in response to stress (Cimino, Owens & Anderson 2003; De la Vega, Hall, Dignan & Wilson 2006), any parallelism in tolerance or resistance to oxygen (or temperature or salinity) stress with HSPs expression in specific crosses still remains to be evaluated, as has been done for the fruit fly.…”

“…In conclusion, the resistance to hypoxic conditions in postlarvae and juvenile Litopenaeus vannamei shrimp appears to be affected by significant maternal effects at the postlarvae stage and dominance in both postlarvae and juvenile. Further work at the molecular level with specific genes involved with stress resistance as the genes coding for some of the stress‐shock proteins might help understand the dominance relationship observed in this work as it has been done in Drosophila (Alahiotis & Stephanou 1982) and in plants (Fender & O'Connell 1990; Jorgensen & Nguyen 1995). At this point, a recommendation on crossing shrimp populations to achieve a better resistance to hypoxic conditions in F1s cannot be realistically carried out, as population genetic differentiation for stress resistance would have to be first evaluated.…”

“…Analysis of variance results are included in the ¢gure. speci¢c hybrids of plants when measured as quantitative expression of HSPs, where it has been found that expression of some HSP types in the bettersurviving F1 occurs at a higher intensity for some of the HSP types derived from one of the parental contributors than the other (Fender & O'Connell 1990;Jorgensen & Nguyen 1995). In shrimp, whereas HSPs are known to be expressed in response to stress (Cimino, Owens & Anderson 2003;De la Vega, Hall, Dignan & Wilson 2006), any parallelism in tolerance or resistance to oxygen (or temperature or salinity) stress with HSPs expression in speci¢c crosses still remains to be evaluated, as has been done for the fruit £y.…”

Electrical signaling in Aloe vera induced by localized thermal stress

“…Heat shock proteins are important homeostatic and defense mechanisms in plants. Kinetics of hsp synthesis, their electrophoretic profiles, and intracellular localization have been characterized in soybean, tomato and other plants [33,34]. In the case of the tomato, exposure to extreme heat activates protease inhibitor (PIN) genes.…”