Transcriptome analysis reveals the regulation of cyclic nucleotide-gated ion channels in response to exogenous abscisic acid and calcium treatment under drought stress in tomato.

Background: Drought stress can limit the growth and development of tomato seedlings and cause considerable loss of tomato yield. Exogenous abscisic acid (ABA) and calcium (Ca2+) can effectively alleviate the damage of drought stress to plants in part because Ca2+ acts as a second messenger in the drought resistance pathway. Although cyclic nucleotide-gated ion channels (CNGCs) are common non-specific Ca2+ osmotic channels in cell membranes, a thorough understanding of the transcriptome characteristics of tomato treated with exogenous ABA and Ca2+ under drought stress is necessary to characterize the molecular mechanism of CNGC involved in tomato drought resistance. Results: There were 12,896 differentially expressed genes in tomato under drought stress, as well as 11,406 and 12,502 differentially expressed genes after exogenous ABA and Ca2+ application, respectively. According to functional annotations and reports, the 19 SlCNGC genes related to Ca2+ transport were initially screened, with 11 SlCNGC genes that were upregulated under drought stress and downregulated after exogenous ABA application. After exogenous Ca2+ application, the data showed that two of these genes were upregulated, while nine genes were downregulated. Based on these expression patterns, we predicted the role of SlCNGC genes in the drought resistance pathway and their regulation by exogenous ABA and Ca2+ in tomato. Conclusion: The results of this study provide foundational data for further study of the function of SlCNGC genes and a more comprehensive understanding of drought resistance mechanisms in tomato.

Composition of Pinot Noir Wine from Grapevine Red Blotch Disease-Infected Vines Managed with Exogenous Abscisic Acid Applications.

Grapevine red blotch disease (GRBD) has negative effects on grape development and impacts berry ripening. Abscisic acid (ABA) is a plant growth regulator involved in the initiation of berry ripening. Exogenous abscisic acid application was compared to an unsprayed control on GRBD-positive Pinot noir vines during two vintages, and the total monomeric anthocyanin, total phenolics, phenolic composition, and volatile profile were measured in wines. In addition, untargeted metabolites were profiled using high-resolution LC-MS/MS. Results showed that the wine composition varied by vintage year and was not consistent with ABA application. Wines from the ABA treatment had a lower total anthocyanin and total phenolic content in one year. The untargeted high-resolution LC-MS/MS analysis showed a higher abundance of phenolic compounds in ABA wines in 2019, but lower in 2018. The wine volatile compounds of ABA treatments varied by vintage. There were higher levels of free ß-damascenone, ß-ionone, nerol, and several fermentation-derived esters, acids, and alcohols in ABA wines, but these were not observed in 2019. Lower 3-isobutyl-2-methoxypyrazine (IBMP) was also observed in wines with ABA treatment in 2019. The results demonstrated that ABA application to the fruit zones did not consistently mitigate the adverse impacts of GRBD on Pinot noir wines.

Study on the Effects of Exogenous Abscisic Acid on Salt-alkali Tolerance of Scrophularia ningpoensis Seed-lings / 中国药房

OBJECTIVE:To study the effects of exogenous abscisic acid(ABA)on salt-alkali tolerance of Scrophularia ning-poensis seedlings,and to provide theoretic evidence for cultivating S. ningpoensis in salt-alkali soil. METHODS:50 S. ningpoensis seedlings were divided into control group,salt-alkali group(75 mmol/L),salt-alkali(75 mmol/L)+ABA low-concentration,medi-um-concentration and high-concentration groups(10,50,100 μmol/L),with 10 plants in each group. 20 days after transplanting, the plants were sprayed with drugs every 4 days. Growth indexes of the plants(length of stem,fresh weight,dry weight,survival rate),physiological indexes [the contents of chlorophyll,soluble sugar (SS),soluble protein (SP) and free proline (Pro)],the contents of MDA and H2O2,the activities of antioxidase [the activities of SOD,POD,CAT,GR] and the contents of Na+ and K+in stem and root were determined in each group 2 weeks later. RESULTS:Compared with control group,stem height and survival rate of S. ningpoensis seedlings,SP,the contents of Na+ and K+ in the stem,the contents of Na+,CAT and GR in the roots were all decreased significantly in salt-alkali group;while chlorophyll,Pro,MDA and H2O2 contents,the content of K+ in the roots and the activities of SOD and POD were all increased significantly(P<0.05 or P<0.01). Compared with salt-alkali group,stem height of S. ningpoensis seedlings,fresh weight and chlorophyll content were increased significantly in salt-alkali+ABA medium-concentra-tion group,while MDA and the content of Na+ in the stem were decreased significantly;dry weight,the contents of SS and SP, the activities of SOD and CAT were increased significantly in salt-alkali+ABA low-concentration and medium-concentration groups, while the SS content was increased in salt-alkali+ABA high-concentration group;stem height and dry weight were decreased signifi-cantly in salt-alkali+ABA high-concentration group;Pro content of salt-alkali+ABA low-concentration and high-concentration groups were decreased significantly;H2O2,Na+ content in the roots were decreased significantly in salt-alkali+ABA low-concentra-tion,medium-concentration and high-concentration groups;while GR activity,K+ content in the stem and roots were increased sig-nificantly;POD activity were decreased significantly in salt-alkali+ABA medium-concentration and high-concentration groups. CON-CLUSIONS:The addition of a certain concentration of exogenous ABA can effectively increase salt-alkali tolerance of S. ningpoen-sis seedlings and strengthen the ability of the plant adapting to salt-alkali environment.