Rhododendron Transcriptome or Gene expression
Rhododendrons (Rhododendron simsii Planch.) are ornamental plants highly valued for their aesthetic appeal and diverse flower colors. Many Rhododendron species are native to acidic soils, where aluminum (Al) toxicity can limit plant growth and development. However, the mechanism of Rhododendron resistance to Al toxicity is rarely reported. In this study, we compared the transcriptional and physiological responses of the Al-resistant cultivar 'Kangnaixin' and the Al-sensitive cultivar 'Baijinpao' of Rhododendron to elucidate the differences in their Al resistance mechanisms. Through de novo transcriptome assembly and analysis, we identified a total of 33.81G of raw data, 2629, 3136, 6876 and 6521 DEGs in the CK14 vs. Al14, CK16 vs. Al16, CK14 vs. CK16, and Al14 vs. Al16 comparison groups. The comparative analysis of Rhododendron cultivars under Al stress revealed significant enrichment of GO terms related to abiotic stress responses and membrane functions, indicating potential disruption of membrane integrity and impacts on plant growth and development. The KEGG enrichment analysis of DEGs revealed that DEGs of both cultivars were significantly enriched in metabolic pathways such as starch and sucrose metabolism, diterpenoid biosynthesis, phenylpropanoid biosynthesis, flavonoid biosynthesis and photosynthesis-antenna protein. This indicated that Al stress can affect the synthesis and metabolism of various compounds and change the chlorophyll content, thereby limiting photosynthesis.Additionally, we identified the Al tolerance homologous gene RsALS3. Overexpression of RsALS3 in Arabidopsis confers high Al tolerance to transgenic plants. The phenotype, Fv/Fm value, instantaneous fluorescence, delayed fluorescence and 820nm light reflection of RSALS3 overexpressed plants were studied. Taken together, this study provides insights into the complex response of Rhododendrons to Al stress and highlights the potential of RsALS3 as a key gene in enhancing Al tolerance. The results contribute to the understanding of Al stress resistance mechanisms in Rhododendrons and pave the way for developing Rhododendron cultivars with improved adaptation to acidic soils.