Effects of Combined Abiotic Stresses on Growth, Trace Element Accumulation, and Phytohormone Regulation in Two Halophytic Species

摘要: Trace element contamination of lands is a serious environmental problem that limits yield and threatens human health. To study the combined effect high salinity toxic levels trace elements on halophytes, performance two marsh species, Atriplex halimus Suaeda fruticosa, grown for 1 month with an irrigation solution supplemented 200 mM NaCl 400 μM Cd2+ or Cu2+ was evaluated. The stress conditions hormone signaling also assessed. Biomass production chlorophyll content decreased under in both whereas had lower impact plant performance. different sensibilities to assayed indicate each metal has plants. Furthermore, deleterious toxicity alleviated when added solution, demonstrating improves tolerance halophytic species cope intoxication. Results show accumulated important quantities roots (Cd2+: 2,690–3,130 μg g−1 DW Cu2+: 2,070–2,770 DW); this finding allows us classify these among hyperaccumulator differently affected endogenous phytohormone contents species. Data suggest essential involvement regulation elements. Therefore, indole-3-acetic acid increased irrigated Cd2+, which suggests auxin may stimulate root promotion growth conditions. Other compounds, classically considered as “stress hormones” showed very patterns accumulation. Whereas, salicylic (SA) leaves response jasmonic (JA), abscisic (ABA) decreased. In leaves, rambling pattern accumulation observed JA ABA suggested lack specific role against toxicity. Together, data SA could act signal detects toxicity, promote general responses abiotic stress.