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Altered gene expression in plants with constitutive expression of a mitochondrial small heat shock protein suggests the involvement of retrograde regulation in the heat stress response
Author(s) -
Rhoads David M.,
White Samuel J.,
Zhou You,
Muralidharan Mrinalini,
Elthon Thomas E.
Publication year - 2005
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.2005.00473.x
Subject(s) - heat shock protein , biology , transgene , arabidopsis , arabidopsis thaliana , microbiology and biotechnology , cauliflower mosaic virus , mitochondrion , chloroplast , gene expression , cytosol , gene , nuclear gene , genetically modified crops , biochemistry , mitochondrial dna , mutant , enzyme
Heat stress can negatively affect crop productivity. One way in which plants attempt to alleviate the effects of heat stress is to induce the expression of genes encoding heat shock proteins (HSPs), including small HSPs (sHSPs). We produced transgenic lines of Arabidopsis thaliana expressing a transgene encoding a maize mitochondrial sHSP, ZmHSP22. The transgene, under the control of the cauliflower mosaic virus 35S promoter, is constitutively highly expressed in these lines. As demonstrated by confocal immunofluorescence microscopy and analyses of isolated mitochondria, ZmHSP22 is directed to the mitochondria of Arabidopsis and is processed into the mature form. These transgenic lines demonstrated altered expression of nuclear genes encoding the endogenous mitochondrial sHSP, AtHSP23.6, chloroplast localized AtHSP25.3, class I cytosolic AtHSP17.4, cytosolic AtHSP70‐1 and chloroplast localized AtHSP70‐6, but not cytosolic AtHSP70‐15, following exposure to heat stress. This suggests that the expression of HSPs can be affected by heat‐induced mitochondrial retrograde regulation. Three‐week‐old plants from the transgenic Arabidopsis lines expressing ZmHSP22 have increased thermotolerance, as measured by the maintenance of higher leaf mass following successive days with short periods of heat stress.