Following infestation by Verticillium wilt, alfalfa (Medicago sativa L.) often shows symptoms such as disease spots, leaf loss, stem, and leaf yellowing, resulting in the decline of alfalfa yield and quality and causing significant losses to the alfalfa industry. The popularization and planting of disease-resistant varieties is the most effective method to prevent and control Verticillium wilt of alfalfa. Therefore, it is particularly important to reveal the resistance mechanism of Verticillium wilt resistant varieties of alfalfa. In this study, the physiological and biochemical indexes were measured on days 7, 14, 21, and 28 after inoculation with Verticillium alfalfae for investigating the response mechanisms of two alfalfa varieties, high-resistant WL343HQ, and low-resistant Dryland. Transcriptome sequencing of alfalfa samples infected with V. alfalfae and uninfected alfalfa samples was performed to analyze the potential functions and signaling pathways of differentially expressed genes (DEGs) by GO classification and KEGG enrichment analysis. Meanwhile, weighted gene co-correlation network analysis (WGCNA) algorithm was used to construct a co-expression network of DEGs. Inoculation with V. alfalfae significantly affected net photosynthetic rate, stomatal conductance, chlorophyll content, MDA content, JA and SA concentrations, and NO and H2O2 contents in both WL343HQ and Dryland inoculated with V. alfalfae. Most of the transcription factors in plants were classified in the WRKY, NAC, and bHLH families. WGCNA analysis showed that the number of transcription factors related to plant growth and disease resistance was higher in the corresponding modules of WL343HQ disease groups on days 7 and 28 (WVa) and (WVd) than in the corresponding modules of Dryland disease groups on days 7 and 21 (HVa) and (HVc). These findings provide data for further gene function validation and also provide a reference for in-depth studies on interactions between plants and pathogens.
1. Phenotypic plasticity and genetic differentiation are the two important processes determining the leaf nutrient resorption among and within plant species, which is critical for understanding the adaptability of plants. However, relative contributions of these two processes have never been quantified at a large geographical scale.2. Here, we investigated intraspecific variations in nutrient resorption among 14 Stipa breviflora populations along a latitude gradient in 2018 and 2019. Furthermore, we sow seeds from these populations in two common gardens at different latitudes and examined the variations in nutrient resorption.3. Our results showed that nitrogen and phosphorus resorption efficiency (NRE and PRE) among S. breviflora populations in nature were positively related to latitude, while this trend disappeared in the common gardens. The heritability of NRE and PRE was 11.45% and 16.78%, respectively. These results suggested that phenotypic plasticity contributed much more than genetic variation to nutrient resorption of S. breviflora. Moreover, the structural equation modelling (SEM) suggested that latitude indirectly affected nutrient resorption mainly by altering soil nutrients. With the increasing of latitude, soil nutrients decreased while nutrient resorption increased. This phenomenon indicated that the main process regulating nutrient resorption is negative feedback to soil nutrient availability.4. Our study provides new insights into the role of nutrient resorption in plant adaptations to geographic variations.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.