GsMYB10 encoding a MYB-CC transcription factor enhances the tolerance to acidic aluminum stress in soybean.

Background: MYB transcription factors (TFs) play crucial roles in the response to diverse abiotic and biotic stress factors in plants. In this study, the GsMYB10 gene encoding a MYB-CC transcription factor was cloned from wild soybean BW69 line. However, there is less report on the aluminum (Al)-tolerant gene in this subfamily.

Results: The GsMYB10 gene was up-regulated by acidic aluminum stress and rich in the roots with a constitutive expression pattern in soybean. It was found that GsMYB10 protein contains the MYB and coiled-coil (CC) domains, localizes in the nucleus and holds transcriptional activity. The analysis of the transgenic phenotype revealed that the taproot length and root fresh weights of the GsMYB10-OE plants were greater than those of the wild type when subjected to AlCl treatments. While the accumulation of Al in root tip of GsMYB10 transgenic plants (59.37 ± 3.59 µg/g) significantly reduced compared with that of wild type (80.40 ± 3.16 µg/g) which were shallowly stained by hematoxylin under the treatments of AlCl. Physiological indexes showed that the proline content significantly increased 39-45% and the malondialdehyde content significantly reduced 37-42% in GsMYB10-OE plants compared with that of wild type. Transcriptomic analysis showed that overexpression of GsMYB10 induced a large number of differentially expressed genes (DEGs) with Al-treatment, which were related to wall modification related genes included PGs (such as Glyma.19g006200, Glyma.05g005800), XTHs (such as Glyma.12g080100, Glyma.12g101800, Glyma.08g093900 and Glyma.13g322500), NRAMPs and ABCs.

Conclusions: In summary, the data presented in this paper indicate that GsMYB10, as a new soybean MYB-CC TF, is a positive regulator and increases the adaptability of soybeans to acidic aluminum stress. The findings will contribute to the understanding of soybean response to acidic aluminum stress.