Fecha de publicación: 27/10/2024 Fuente: Citrus Byproducts Extraction Abstract
The response of plants to changing environmental conditions is mediated by endogenous phytohormones of which concentration and activity can be altered by the exogenous application of plant growth regulators (PGRs). The present study was conducted to investigate the effects of foliar application of distilled water (ddH2O) and methyl jasmonate (MeJA—5 and 50 µM) under drought stress (15 and 5% of soil water content—SWC) on the endogenous phytohormone status of Impatiens walleriana. The following classes of phytohormones were analyzed by HPLC–MS: abscisic acid (ABA) and its metabolic intermediates, jasmonates, salicylic acid (SA), cytokinins (CKs), and auxin indole-3-acetic acid (IAA). The results showed that plant leaves sprayed with 50 μM MeJA during severe drought (5% SWC) had the highest concentrations of ABA and jasmonic acid (JA). In addition, the plant leaves treated with 50 μM MeJA at 15% SWC showed a significantly increased JA content. In plant groups treated with ddH2O and 50 µM MeJA, the content of another jasmonate, jasmonic acid-isoleucine (JA-Ile), increased at 5% SWC. Interestingly, foliar application of MeJA did not induce changes in endogenous MeJA content in I. walleriana leaves. Similarly, no changes in SA or CK content were observed in any of the treated plant groups. On the other hand, an increase in the auxin IAA was observed in plants sprayed with ddH2O and 50 µM MeJA at 5% SWC. The results from this study indicate that MeJA foliar application could significantly affect the endogenous phytohormonal status of I. walleriana, which changes are fundamental in overall plant drought experience. According to the obtained results, the concentration of ABA and jasmonates changed the most significantly, indicating a possible overlap of their signaling pathways, as well as interaction with other phytohormones.