HSP21 | Chloroplastic heat shock protein

Overexpression of HsfA2 leads to constitutive expression of its target genes in rps1 mutant plants.(A) qRT-PCR analysis of mRNA levels of the representative HsfA2 target genes in the fully-extended leaves of WT, rps1 and rps1 with a 35S:HsfA2 cDNA transgene plants. Actin2 was used as the internal standard. Error bars indicate standard deviations of three technical replicates, and the results were consistent in three biological replicates. (B) Western blot analysis of thylakoid membrane proteins extracted from the leaves of the genotypes indicated in (A). Equal protein loading was determined by contents (2 µg) of chlorophyll in thylakoid membrane extracts according to (Peng et al., 2006). (C) Protein levels of HSP21, encoded by HsfA2 target gene Hsp25.3, in leaves of the plants described in (A) were analyzed by western blots with a polyclonal antibody against HSP21.

Effects of gain and loss of function of HaHSFA9 on the accumulation of plastidial sHSPs in seeds and seedlings.Immunoblot detection with the anti-HSP21 antibody at 1/2,500 dilution. Different transgenic lines (T) were compared with sibling non-transgenic (NT) lines. From top to bottom: DS10:A9 seeds, DS10:A9M3 seeds, and 35S:A9 seedlings. Protein amounts loaded: 25 ?g total protein for the seed samples and for the 40°C seedling sample; 15 ?g for the rest of seedling samples. Enhanced detection conditions were used for the DS10:A9M3 samples with respect to DS10:A9 (90 min instead of 5 min exposure, compare the respective NT signals). The high-level accumulation of plastidial sHSPs in unstressed seedlings of the 35S:A9 lines was compared with that in NT seedlings after heat-acclimation for 3 h at 40°C (40°C). Molecular mass markers (kD) are indicated to the left.