MdTyDc Overexpression Improves Alkalinity Tolerance in Malus domestica

Abstract

Tyrosine is decarboxylated to tyramine by TYDC (Tyrosine decarboxylase) and then hydroxylated to dopamine, which is involved in plant response to abiotic stress. However, little is known about the function of MdTyDc in response to alkaline stress in plants. In our study, it was found that the expression of MdTyDc was induced by alkaline stress. Therefore, the apple plants overexpressing MdTyDc was treated with alkali stress, and we found that MdTyDc played an important role in apple plants’ resistance to alkali stress. Our results showed that the restriction on the growth, the decrease of membrane permeability and the accumulation of Na+ were alleviated to various degrees in MdTyDc transgenic plants under alkali stress. In addition, overexpression of MdTyDc enhanced the root activity and photosynthetic capacity, and improved the enzyme activity related to N metabolism, thus promoting N absorption. It is noteworthy that the dopamine content of these three transgenic lines is significantly higher than that of WT. In summary, these findings indicated that MdTyDc may enhance alkaline tolerance of apples by mediating dopamine content, mainly by maintaining high photosynthetic capacity, normal ion homeostasis and strong nitrogen absorption capacity.

The Alkali Tolerance of Broomcorn Millet (Panicum miliaceum L.) at the Germination and Seedling Stage: The Case of 296 Broomcorn Millet Genotypes

“…This result suggests that the leaves of BM can resist and adapt to alkali stress by activating the osmotic regulation system. This is in line with the conclusion that overexpression of MdTyDc promotes the accumulation of proline in apples, thereby reducing the damage associated with alkali stress (Liu et al, 2021). Similar conclusions have also been drawn when plants encounter heavy metal stress (Huang and Wang, 2010;Huang et al, 2019).…”

Genome-Wide Identification of PRP Genes in Apple Genome and the Role of MdPRP6 in Response to Heat Stress

“…According to previous method, tobacco leaves were excised and scored according to their fresh weight, rehydrated and dry weights, and RWC = (fresh weight − dry weight)/(rehydrated weight−dry weight)", and this was used to calculate RWC of leaves [60]. Chlorophyll content was determined by UV-2250 spectrophotometer (Shimadzu, Kyoto, Japan) after leaf chlorophyll was extracted with 80% acetone, as described by Liu et al (2021) [61]. The activities of SOD, POD, and the MDA, H 2 O 2 , and O 2− content, were detected with their corresponding detection kits (Suzhou Comin Biotechnology Co., Ltd., Suzhou, China).…”

Heterologous Expression of the Melatonin-Related Gene HIOMT Improves Salt Tolerance in Malus domestica

“…The experiments performed in a hydroponic laboratory in Northwest A & F University Yangling (34 • 20 ′ N, 108 • 24 ′ E), Shaanxi Province, China. Plants growth with condition included a 14 h photoperiod (the light intensity was 160 µmol m −2 •s −1 ), 24 ± 2 • C/16 ± 2 • C day/night and 60 ± 5% relative humidity [55]. After 2 weeks of pre-adaptation, plants of consistent size and healthy were picked for treatment.…”

“…During the whole process of salt treatment, every three days we measured Pn, Ci, gs, and Tr using a CIRAS-3 portable photosynthesis system (CIRAS-3, PP Systems, Amesbury, MA, USA) between 9:00 and 11:00. The instrument parameter setting referred to the description of Liu et al [55]. For each treatment, 5-8 functional leaves at the same position are selected for the measurement of photosynthetic parameters.…”