1. MTB1 to MTB3 Negatively Regulate Diverse Aspects of JA Responses.
MTB1 to MTB3 Negatively Regulate Diverse Aspects of JA Responses. (A) and (B) RT-qPCR assays of the expression of TomLoxD, JA2L, TD, and PI-II in wild-type, MTB-RNAi-2#, MTB-RNAi-8#, MTB1-OE-5#, and MTB1-OE-6# plants in response to mechanical wounding (A) and MeJA treatment (B). For (A), 18-d-old seedlings of the indicated tomato genotypes with two fully expanded leaves were mechanically wounded using a hemostat on both leaves for the indicated times before extracting total RNAs for RT-qPCR assays. For (B), 18-d-old seedlings of the indicated tomato genotypes with two fully expanded leaves were exposed to MeJA vapor for the indicated times before extracting total RNAs for RT-qPCR assays. (C) Anthocyanin contents of the 7-d-old seedlings in wild-type, MTB-RNAi-2#, MTB-RNAi-8#, MTB1-OE-5#, and MTB1-OE-6# plants grown on Murashige and Skoog (MS) medium containing indicated concentrations of JA. FW, fresh weight. (D) Root growth inhibition assay of 7-d-old seedlings of wild-type, MTB-RNAi-2#, MTB-RNAi-8#, MTB1-OE-5#, and MTB1-OE-6# plants grown on MS medium supplied with indicated concentrations (µM) of JA. Data represent means ± sd (n = 20). (E) Expression of PI-II in wild-type, MTB-RNAi-2#, MTB-RNAi-8#, MTB1-OE-5#, and MTB1-OE-6# plants subjected to H. armigera larvae. Plants were harvested at the indicated time points during the feeding trial for RNA extraction and RT-qPCR analysis. (F) Average weight of larvae recovered at the end of day 4 of the feeding trial using whole plants of wild-type, MTB-RNAi-2#, MTB-RNAi-8#, MTB1-OE-5#, and MTB1-OE-6# genotypes. Data represent means ± sd (n = 15). Each symbol represents the weight of an individual larva. (G) Expression of PR-STH2 in wild-type, MTB-RNAi-2#, MTB-RNAi-8#, MTB1-OE-5#, and MTB1-OE-6# plants treated with B. cinerea suspensions. Five-week-old plants were spotted with a 5-μL spore suspension (106 spores/mL). Leaves were harvested 24 h after inoculation for RNA extraction and RT-qPCR analysis. (H) Growth of B. cinerea in wild-type, MTB-RNAi-2#, MTB-RNAi-8#, MTB1-OE-5#, and MTB1-OE-6# plants. Detached leaves from 5-week-old tomato plants were spotted with a 5-μL spore suspension (106 spores/mL). The lesion areas were analyzed at 3 d after inoculation. Data represent means ± sd (n = 9). (I) Expression of PR1b in wild-type, MTB-RNAi-2#, MTB-RNAi-8#, MTB1-OE-5#, and MTB1-OE-6# plants infected with Pst DC3000. Five-week-old plants were vacuum infiltrated with Pst DC3000 (0.5 × 10−5 cfu/mL). Leaves were harvested 24 h after inoculation for RNA extraction and RT-qPCR analysis. (J) Growth of Pst DC3000 in wild-type, MTB-RNAi-2#, MTB-RNAi-8#, MTB1-OE-5#, and MTB1-OE-6# plants. Data represent means ± sd (n = 6). For (A), (B), (C), (E), (G), and (I), data represent means ± sd (n = 3). For all panels, asterisks indicate significant differences from the wild type according to Student’s t test at *, P < 0.05; **, P < 0.01; and ***, P < (Supplemental Data Set 2).
Yuanyuan Liu et al. Plant Cell 2019;31:
©2019 by American Society of Plant Biologists