E3 ubiquitin ligase PbrATL18 is a positive factor in pear resistance to drought and Colletotrichum fructicola infection

ATL Protein Family: Novel Regulators in Plant Response to Environmental Stresses

“…In contrast, CAT and PPO levels in the control group were notably higher than those in the pTRV-PbrATL18 -silenced plants, although the absolute levels were relatively low. In summary, these results suggest that pTRV-PbrATL18 -silenced pear plants exhibit increased susceptibility to C. fructicola compared to the control group …”

“…Further investigations into the activities of POD, CAT, and SOD revealed significantly lower levels of these enzymes in pTRV-PbrATL18 -silenced plants than in the control group. In conclusion, compared to the control group, PbrATL18 -silenced plants showed increased susceptibility to drought stress, which was associated with a reduction in the in vivo activity of antioxidant enzymes …”

“…Although it is known that PbrATL18 regulates the levels of other targeted proteins by ubiquitination, thereby promoting a positive effect on plant stress resistance, the exact mechanisms involved are not fully understood. Therefore, further investigation is warranted to elucidate the underlying molecular mechanisms …”

“…Under conditions of drought stress signaling, the rapid elevation in PbrATL18 expression led to enhanced activities of superoxide dismutase (SOD), CAT, and peroxidase (POD) within the plants. This, in turn, maintains ROS levels in a relatively stable state and improves drought resilience in plants …”

“…In summary, these results suggest that pTRV-PbrATL18-silenced pear plants exhibit increased susceptibility to C. f ructicola compared to the control group. 92 Furthermore, in C. f ructicola-infected plants, the expression of PbrATL18 rapidly increased, leading to increased CAT, PAL, CHI, and PPO activities while maintaining the relevant substrates' homeostasis. Although it is known that PbrATL18 regulates the levels of other targeted proteins by ubiquitination, thereby promoting a positive effect on plant stress resistance, the exact mechanisms involved are not fully understood.…”