Jungkunz I, Link K, Vogel F, Voll L, Sonnewald S, Sonnewald U (2011)
Publication Status: Published
Publication Type: Journal article
Publication year: 2011
Publisher: WILEY-BLACKWELL
Book Volume: 66
Pages Range: 983-995
Journal Issue: 6
DOI: 10.1111/j.1365-313X.2011.04558.x
Arabidopsis thaliana contains 18 genes encoding Hsp70s. This heat shock protein superfamily is divided into two sub-families: DnaK and Hsp110/SSE. In order to functionally characterize members of the Hsp70 superfamily, loss-of-function mutants with reduced cytosolic Hsp70 expression were studied. AtHsp70-1 and AtHsp70-2 are constitutively expressed and represent the major cytosolic Hsp70 isoforms under ambient conditions. Analysis of single and double mutants did not reveal any difference compared to wild-type controls. In yeast, SSE protein has been shown to act as a nucleotide exchange factor, essential for Hsp70 function. To test whether members of the Hsp110/SSE sub-family serve essential functions in plants, two members of the sub-family, AtHsp70-14 and AtHsp70-15, were analysed. Both genes are highly homologous and constitutively expressed. Deficiency of AtHsp70-15 but not of AtHsp70-14 led to severe growth retardation. AtHsp70-15-deficient plants were smaller than wild-type and exhibited a slightly different leaf shape. Stomatal closure under ambient conditions and in response to ABA was impaired in the AtHsp70-15 transgenic plants, but ABA-dependent inhibition of germination was not affected. Heat treatment of AtHsp70-15-deficient plants resulted in drastically increased mortality, indicating that AtHsp70-15 plays an essential role during normal growth and in the heat response of Arabidopsis plants. AtHsp70-15-deficient plants are more tolerant to infection by turnip mosaic virus. Comparative transcriptome analysis revealed that AtHsp70-15-deficient plants display a constitutive stress response similar to the cytosolic protein response. Based on these results, AtHsp70-15 is likely to be a key factor in proper folding of cytosolic proteins, and may function as nucleotide exchange factor as proposed for yeast.
APA:
Jungkunz, I., Link, K., Vogel, F., Voll, L., Sonnewald, S., & Sonnewald, U. (2011). AtHsp70-15-deficient Arabidopsis plants are characterized by reduced growth, a constitutive cytosolic protein response and enhanced resistance to TuMV. Plant Journal, 66(6), 983-995. https://dx.doi.org/10.1111/j.1365-313X.2011.04558.x
MLA:
Jungkunz, Isabel, et al. "AtHsp70-15-deficient Arabidopsis plants are characterized by reduced growth, a constitutive cytosolic protein response and enhanced resistance to TuMV." Plant Journal 66.6 (2011): 983-995.
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