Exon–intron structure analyses of CsHSP90 (A), CsHSP70 (B), and CssHSP (C) genes. The yellow sections represent exons, and the grey parts indicate introns. CI, CII, CV, and CVI: cytoplasm I, II, V and VI; ER: endoplasmic reticulum, MI: mitochondria I; P: plastid; and Px: peroxide.