Regulation of miR319b-Targeted SlTCP10 during the Tomato Response to Low-Potassium Stress

Potassium deficiency confines root growth and decreases root-to-shoot ratio, thereby limiting root K acquisition. This study aimed to identify the regulation network of microRNA319 involved in low-K stress tolerance in tomato ( ). SlmiR319b-OE roots demonstrated a smaller root system, a lower number of root hairs and lower K content under low-K stress. We identified as the target of miR319b using a modified RLM-RACE procedure from some SlTCPs' predictive complementarity to miR319b. Then, -regulated (an NAC transcription factor) influenced the response to low-K stress. CR- (CRISPR-Cas9- ) lines showed the same root phenotype to SlmiR319-OE compared with WT lines. OE- (Overexpression- ) lines showed higher root biomass, root hair number and K concentration in the roots under low-K conditions. Furthermore, has been reported to promote abscisic acid (ABA) biosynthesis. Therefore, increases low-K tolerance via ABA. In conclusion, enlarging root growth and K absorption by the expression of SlmiR319b-regulated , mediating in roots, could provide a new regulation mechanism for increasing K acquisition efficiency under low-K stress.