The Effect of Proline Applications on Heat Shock Proteins and Stress Tolerance in Peppers Under Low Temperature Stress

Sergül Ergin; Tuğçe Nur Çetin

doi:10.24925/turjaf.v14i9.2509-2515.8968

Authors

Sergül Ergin Eskisehir Osmangazi University, Faculty of Agriculture, Agricultural Biotechnology Department, Eskisehir, Türkiye https://orcid.org/0000-0002-7720-5536
Tuğçe Nur Çetin Eskisehir Osmangazi University, Faculty of Agriculture, Agricultural Biotechnology Department, Eskisehir, Türkiye https://orcid.org/0000-0003-1469-0252

DOI:

https://doi.org/10.24925/turjaf.v14i9.2509-2515.8968

Keywords:

Capsicum annuum L., HSP23, HSP60, Low Temperature Stress, Proline

Abstract

This study investigated the physiological and molecular changes induced by low temperature stress in pepper (Capsicum annuum L.) plants and the effects of exogenous proline applications under these stress conditions. Seeds of the ‘Yalova Çorbacı 12’ cultivar were grown in trays containing a mixture of peat, soil, and perlite (1:1:1), and when the seedlings reached the 3–4 leaf stage, 0, 5, 10, and 20 mM proline solutions were applied as foliar sprays three times at three-day intervals. Following the treatments, plants were exposed to low temperature stress (+8 °C) for three (72 hours) days. Cellular damage, proline content, and total soluble protein content were determined in leaf tissues, and protein profiles were also analysed. It was found that cellular damage was higher in plants exposed to low temperature stress without proline application, whereas proline-treated plants showed reduced damage, with the lowest damage observed at 5 mM proline. Proline content decreased in the stressed plants without proline application, while it increased in proline-treated plants. Although total soluble protein content decreased under low temperature stress, it was higher in proline-treated plants, with the highest value recorded at 5 mM. Protein analyses revealed the presence of protein bands with varying intensities depending on the treatments. According to immunoblot results, HSP60 and HSP23 increased under low temperature stress and reached their highest levels at 5 mM proline application. In conclusion, exogenous proline application enhanced tolerance to low temperature stress, with 5 mM identified as the most effective concentration.

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