Developmentally and stress-induced small heat shock proteins in cork oak somatic embryos

Abstract

The timing and tissue localization of small heat shock proteins (sHSPs) during cork oak somatic embryo development was investigated under normal growing culture conditions and in response to stress. Western blot analyses using polyclonal antibodies raised against cork oak recombinant HSP17 showed a transient accumulation of class I sHSPs during somatic embryo maturation and germination. Moreover, the amount of protein increased at all stages of embryo development in response to exogenous stress. The developmentally accumulated proteins localized to early differentiating, but not the highly dividing, regions of the root and shoot apical meristems. By contrast, these highly dividing regions were strongly immunostained after heat stress. Findings support the hypothesis of a distinct control for developmentally and stress-induced accumulation of class I sHSPs. The possible role of sHSPs is discussed in relation to their tissue specific localization.

Seasonal variation in transcript accumulation in wood-forming tissues of maritime pine (Pinus pinaster Ait.) with emphasis on a cell wall glycine-rich protein

“…In plants, it is well known that LMW HSPs are produced in response to various stresses (Vierling 1991;Waters et al 1996;Costa et al 1998). Synthesis also occurs during developmental processes such as pollen or seed maturation (Puigderrajols et al 2002) and early seedling growth (Kaukinen et al 1996). In Douglas fir, expression of a class-I LMW HSP was shown to be under the control of several plant growth regulators (Kaukinen et al 1996).…”

A 10-kDa class-CI sHsp protects E. coli from oxidative and high-temperature stress

“…The 2D-electrophoresis pattern of rQsHsp10.4-CI showing a single spot and the series of spots in the ca. 10-kDa region of stressed plant tissues would either indicate the presence of post-translational modifications (as was suggested for QsHsp17.4-CI, Puigderrajols et al 2002) or that multiple genes code for ca. 10-kDa sHsp-CIs.…”

“…10-kDa and 17-kDa regions. In the 17-kDa region, the detected set of immunospots corresponds to QsHsp17.4-CI (see Puigderrajols et al 2002). These polypeptides were highly accumulated in cork, wood and in heat-stressed plantlets, but were scarce in non-stressed plantlets and could not be detected in those oxidatively stressed.…”

Comparative proteomic analysis of longan (Dimocarpus longan Lour.) seed abortion

“…HSPs also act as chaperonins and have strong cytoprotective effects, maintaining proteins in their functional conformations, preventing aggregation of non-native proteins, refolding of denatured proteins to regain their functional conformation, and removal of nonfunctional but potentially harmful polypeptides (arising from misfolding, denaturation, or aggregation) (Gallie et al 1997;Hashimoto and Komatsu 2007). sHSP (HSP 17) played an important role in seed and embryo development (Puigderrajols et al 2002). Inhibition of sHSPs expression may lead to seed abortion (Wehmeyer and Vierling 2000).…”