Expression of Selected <em>Ginkgo </em><em>biloba </em>Heat Shock Protein Genes After Cold Treatment Could Be Induced by Other Abiotic Stress

Abstract

Heat shock proteins (HSPs) play various stress-protective roles in plants. In this study, three <em>HSP</em> genes were isolated from a suppression subtractive hybridization (SSH) cDNA library of <em>Ginkgo biloba</em> leaves treated with cold stress. Based on the molecular weight, the three genes were designated <em>GbHSP16.8</em>, <em>GbHSP17</em> and <em>GbHSP70</em>. The full length of the three genes were predicted to encode three polypeptide chains containing 149 amino acids (Aa), 152 Aa, and 657 Aa, and their corresponding molecular weights were predicted as follows: 16.67 kDa, 17.39 kDa, and 71.81 kDa respectively. The three genes exhibited distinctive expression patterns in different organs or development stages. <em>GbHSP16.8</em> and <em>GbHSP70</em> showed high expression levels in leaves and a low level in gynoecia, <em>GbHSP17</em> showed a higher transcription in stamens and lower level in fruit. This result indicates that <em>GbHSP16.8</em> and <em>GbHSP70 </em>may play important roles in <em>Ginkgo</em> leaf development and photosynthesis, and <em>GbHSP17</em> may play a positive role in pollen maturation. All three <em>GbHSPs</em> were up-regulated under cold stress, whereas extreme heat stress only caused up-regulation of <em>GbHSP70</em>, UV-B treatment resulted in up-regulation of <em>GbHSP16.8</em> and <em>GbHSP17</em>, wounding treatment resulted in up-regulation of <em>GbHSP16.8</em> and <em>GbHSP70</em>, and abscisic acid (ABA) treatment caused up-regulation of <em>GbHSP70</em> primarily.

Keywords

• heat shock proteins
• SSH
• cold stress
• heat stress
• abiotic stress
• &lt;em&gt;Ginkgo biloba&lt;/em&gt;