Physiological and Gene Expression Response of Interspecific Hybrids of Fraxinus mandshurica × Fraxinus americana to MJ or SNP under Drought

Drought affects the growth and production of Fraxinus tree species, such as precious woody plant mandshurica. Based on interspecific hybrid F1 combinations, D110 plants F. mandshurica × americana with strong drought resistance were selected for this study. To further reveal their heterosis mechanism under drought, in study, an analysis was conducted pertaining to physiological indexes gene expression related key changes materials 5 yr seedlings female male parental controls (D113 4–3) response well addition sodium nitrate (SNP, a donor nitric oxide) methyl jasmonate (MJ, jasmonate) signal molecules after drought. The results showed that stress, performed significantly better than parents, especially compared D113, (the height 29.48% higher), photosynthesis net photosynthetic rate 38.4% peroxidation increase MDA content 71.77% lower), defense enzyme activity (SOD POD activities 36.63% 65.58% hormone contents (ABA, IAA GA 33.9%~51.2% higher) LHY TOC1 rhythmic genes 131.97%~165.81% higher). When exogenous additive agent (SNP or MJ) applied negative effects effectively alleviated increased from 22.76% 22.32% comparison conditions); meanwhile, higher parents. Further SNP MJ also indicated can recover faster parents application MJ. This article provides new ideas revealing hybrids supplies effective measures improving