Kunkun Wu

The Xinjiang wheat variety ‘Xindong 22’ was used as experimental material. Two soil moisture treatments were established: control (CK, 70–75% field capacity), drought (X1, 60–65%). The photosynthetic characteristics and resistance physiological indexes of wheat leaves under different stress levels were analyzed, and RNA-Seq technology was used to conduct transcriptome sequencing and analysis were performed on wheat leaves. The results showed that under drought stress, superoxide dismutase (SOD) activity was significantly enhanced, while peroxidase (POD) activity decreased. Soluble sugar and proline contents also increased. These changes likely enhanced reactive oxygen species scavenging, thereby reducing the content of malondialdehyde in the leaves. Meanwhile, under the X1 treatment, stomatal conductance and transpiration rate of wheat leaves showed a slow decreasing trend, the intercellular CO₂ concentration decreased slightly, the decline in Fv/Fm was relatively small, and the value of the non-photochemical quenching coefficient gradually increased. Transcriptome analysis identified 1881 differentially expressed genes (DEGs). Notably, drought stress induced the up-regulation of key genes involved in the ABA signaling pathway (e.g., SnRK2 and ABF) and the MAPK cascade, suggesting their crucial roles in mediating drought responses in this wheat variety. In the jasmonic acid signaling pathway, MYC2 functions as a positive regulator by interacting with JAZ proteins. These findings demonstrate that Xinjiang wheat employs integrated physiological and molecular strategies to cope with drought stress.

Investigating the physiological responses and resistance mechanisms in plants under drought stress provides critical insights for optimizing irrigation water utilization efficiency and promoting the development of irrigation science. In this study, cotton seedlings were cultivated in a light incubator. Three drought stress levels were applied: mild (M1, 50–55% field moisture), moderate (M2, 45–50%), and severe (M3, 40–45%). Transcriptome analysis was performed under mild and severe stress. The results revealed that differentially expressed genes (DEGs) related to proline degradation were down-regulated and proline content increased in cotton. Under different stress treatments, cotton exhibited a stress-intensity-dependent regulation of carbohydrate metabolism and soluble sugar content decreased and then increased. And the malondialdehyde content analysis revealed a dose-dependent relationship between stress intensity and membrane lipid peroxidation. Stress activated the antioxidant system, leading to the down-regulation of DEGs for reactive oxygen species production in the mitogen-activated protein kinase (MAPK) signaling pathway. Concurrently, superoxide dismutase activity and peroxidase content increased to mitigate oxidative damage. Meanwhile, the photosynthetic performance of cotton seedlings was inhibited. Chlorophyll content, stomatal conductance, the net photosynthetic rate, the transpiration rate and water use efficiency were significantly reduced; intercellular carbon dioxide concentration and leaf stomatal limitation value increased. But photosynthesis genes (e.g., PSBO (oxygen-evolving enhancer protein 1), RBCS (ribulose bisphosphate carboxylase small chain), and FBA2 (fructose-bisphosphate aldolase 1)) in cotton were up-regulated to coordinate the photosynthetic process. Furthermore, cotton seedlings differentially regulated key biosynthesis and signaling components of phytohormonal pathways including abscisic acid, indoleacetic acid and gibberellin. This study elucidates the significant gene expression of drought-responsive transcriptional networks and relevant physiological response in cotton seedlings and offers a theoretical basis for developing water-saving irrigation strategies.

In this study, the dominant pathogenic fungus of gray spot disease in loquat, which was isolated from postharvest decaying loquat fruits in Zhenjiang, was identified as Pestalotiopsis vismiae (P. vismiae) by morphological characteristics and DNA sequencing. At the same time, a strain of yeast E1, which could effectively inhibit the pathogen, was isolated from the loquat leaves and soil and identified as Metschnikowia pulcherrima (M. pulcherrima) by morphological and molecular biological characteristics. It significantly reduced the natural decay of loquat fruits without affecting fruit quality. Metschnikowia pulcherrima E1 (M. pulcherrima E1) exhibited significant biocontrol efficacy against P. vismiae, the causal agent of gray spot in loquat, reducing disease incidence to 22.73% compared to 100% in the control group. Transcriptome analysis revealed 1444 differentially expressed genes (DEGs) (1111 upregulated, 333 downregulated), with key genes (CML19, XTH23, GSTU10) validated by RT-qPCR. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis highlighted enrichment in plant–pathogen interactions, glutathione metabolism, and phenylpropanoid biosynthesis. These findings provided molecular insights into yeast-induced resistance, bridging biocontrol applications with mechanistic studies.