Transcriptome Analysis of Genes Involved in Aluminum Stress Responses in Peanut (Arachis Hypogaea L.)

Background: Aluminum (Al) contamination inhibits plant growth and development, however, mechanisms involved in Al stress tolerance in peanut ( Arachis hypogaea L.) were rarely studied. The present study was comprised of four Al levels i.e., 0, 1.25, 2.5 and 5 mmol l −1 AlCl 3 .18H 2 O regarded as Al0, Al1, Al2, and Al3. The respective concentrations were added in Hoagland nutrient solution and replaced every three days. Result Results revealed that seeding length low Al concentration (Al1) treatment had no noticeable effect on seeding lenght, while higher Al concentration (Al2 and Al3) treatment significantly inhibited seeding lenght. The differentially expressed genes (DEGs) of plant hormone metabolism pathway were significantly enriched whereas the contents of salicylic acid (SA) and abscisic acid (ABA) were up-regulated, and jasmonic acid (JA) were down-regulated to different levels. Moreover, transcription factors (TFs) and ALMT9 and FRDL1 genes were up-regulated at higher Al concentration and down-regulated at the lowest Al concentration (Al1). Conclusions Overall, Higher Al concentrations up-regulated the expression of transcription factors (TFs), and ALMT9 and FRDL1 genes to resist the stress of high Al concentrations whereas transcriptome analysis revealed that Al stress tolerance is closely related to endogenous hormone contents i.e., salicylic acid (SA), abscisic acid (ABA), and jasmonic acid (JA). This study preliminarily analyzed the molecular mechanism of Al tolerance in peanut and provided a theoretical rationale for developing new Al-tolerant peanut cultivars.