Plants are sessile organisms that have to cope with different environmental stresses during their life cycle. Photosystem II is one of the most labile processes affected by abiotic stress. The chloroplast small heat shock proteins (Cp-sHSPs) are known to protect photosystem II and thylakoid membranes during heat stress. Previously, we reported several cis-regulatory elements in the promoter regions of Cp-sHSPs of Chenopodium album (Shakeel et al., Plant Physiol Biochem 49:898-908, 2011) and differential regulation of a novel Cp-sHSP family member, CaHSP26.13p, under heat and metal stress (Haq et al., Plant Cell Reports 31:1943-1957, 2012). To further explore the role of Cp-sHSPs in plant stress tolerance, we subjected C. album plants to salt, drought, or cold stress and characterized the accumulation of Cp-sHSP transcripts. Full-length Cp-sHSP transcripts were analyzed for the presence of characteristic domains of Cp-sHSPs and compared with previously known Cp-sHSP homologs and orthologs. Analysis showed that the CaHSP26.13p transcript is differentially regulated under heat, metal, cold, drought, or salt stress. Immunoblot analysis revealed the presence of the precursor proteins (∼26 kDa) synthesized from this transcript. The expression level varied depending on the conditions. Generally, transcript and protein levels were not correlated. This study demonstrates that a single C. album Cp-sHSP had multiple roles under a variety of environmental stresses.
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Plant Science