Growth, physiological, and molecular responses of three phaeophyte extracts on salt-stressed pea (Pisum sativum L.) seedlings

Abstract Seaweeds are a viable bioresource for suffering plants against salt stress. The alleviating capacity of extracts from three brown algae (Sargassum vulgare, Colpomenia sinuosa, and Pandia pavonica) in pea (Pisum sativum L.) was investigated in this study. Pea seeds were primed for 2 h either with seaweed extracts (SWEs) or distlled water. Seeds were then subjected to salinity levels of 0.0, 50, 100, and 150 mM NaCl. On 21st day seedlings were harvested for growth, physiological and molecular investigations. SWEs were helpful in reducing the adverse effects of salinity on pea, with S. vulgare extract being the most effective. Furthermore, SWEs diminished the effect of NaCl-salinity on germination, growth rate, pigments content and raised the osmolytes proline and glycine betaine levels. On the molecular level, two low-molecular weight proteins were newly synthesized by the NaCl treatments and three by priming of pea seeds with SWEs. The number of inter-simple sequence repeats (ISSR) markers substantially increased from 20 in the control seedlings to 36 in 150 mM NaCl-treated seedlings, including four unique markers. Priming with seaweed extract triggered more markers than the control, however about ten of the salinity-induced markers were not detected following seed priming before NaCl treatments. By priming with SWEs, seven unique markers were elicited. All in all, priming with SWEs alleviated salinity stress on pea seedlings. The response of plants to salt stress and priming with SWEs is reflected by the synthesis of salinity responsive proteins and ISSR markers.