Improving Salt Tolerance in Safflower Plants through Exogenous Application of Penconazole

Abstract

Core Ideas Penconazole decreases the negative effects of salinity in safflower. Penconazole helps safflower to cope with salinity by the regulation of compatible solutes. Penconazole increases the expression of key genes responsible in defense system. Penconazole increases the activity of enzymatic and non‐enzymatic antioxidants. It has been shown that penconazole (PEN) acts as an endogenous signal molecule responsible for inducing stress tolerance in plants. The effect of PEN (15 mg L−1) and sodium chloride (0, 100, and 200 mM NaCl) on some biochemical and molecular responses of safflower (Carthamus tinctorius L.) were studied. Results revealed that K+ and Ca2+ contents, and some growth parameters decreased under salinity however, Na+ content, compatible solutes, H2O2 and malondialdehyde (MDA) levels, phenolic compounds, phenylalanine ammonia‐lyase (PAL) gene expression, and antioxidant enzyme activities increased. The exogenous PEN had a positive effect on K+ and Ca2+ contents, growth parameters, compatible solutes, antioxidant enzyme activities, and H2O2 content, but decreased Na+ and MDA contents. In addition, quantitative real‐time (qRT)‐polymerase chain reaction (PCR) analysis showed that exogenous PEN induced expression of PAL gene in both untreated and salt‐treated plants. Our data indicate that PEN helps safflower plants to better cope with salt stress. The results provide new insights to mechanisms that help regulate salinity resistance in safflower. Penconazole may be considered as a foliar application to ameliorate salinity effects, due to its low price and availability.