Transcriptome responses of two Halophila stipulacea seagrass populations from pristine and impacted habitats, to single and combined thermal and excess nutrient stressors, reveal local adaptive features and core stress-response genes
Authors: Nguyen, H. M., Yaakov, B., Beca-Carretero, P., Procaccini, G., Wang, G., Dassanayake, M., Winters, G., Barak, S.
The study examined transcriptomic responses of the tropical seagrass Halophila stipulacea from a pristine and an impacted site under single and combined thermal and excess nutrient stress in mesocosms. Combined stress caused greater gene reprogramming than individual stresses, with thermal effects dominating and the impacted population showing reduced plasticity but higher resilience. Core stress‑response genes were identified as potential early field indicators of environmental stress.
The study investigated whether nitrogen‑fixing rhizobial symbiosis in Medicago truncatula primes defense against the pea aphid Acyrthosiphon pisum. Metabolite profiling (LC‑MS, GC‑MS) and qPCR revealed that symbiotic plants uniquely accumulated triterpenoid saponins and up‑regulated flavonoid‑biosynthetic genes after aphid infestation, suggesting that NFS enhances pest‑specific defenses.