CDPKs (Ca²⁺-Dependent Protein Kinases) are very important regulators in plant response to abiotic stress. The molecular regulatory mechanism of CDPKs involved in salt stress tolerance remains unclear, although some CDPKs have been identified in salt-stress signaling. Here, we investigated the function of an Arabidopsis CDPK, CPK12, in salt-stress signaling. The CPK12-RNA interference (RNAi) mutant was much more sensitive to salt stress than the wild-type plant GL1 in terms of seedling growth. Under NaCl treatment, Na⁺ levels in the roots of CPK12-RNAi plants increased and were higher than levels in GL1 plants. In addition, the level of salt-elicited H₂O₂ production was higher in CPK12-RNAi mutants than in wild-type GL1 plants after NaCl treatment. Collectively, our results suggest that CPK12 is required for plant adaptation to salt stress.

Chlorogenic acid (CGA), a natural phenolic compound, is an important bioactive compound, and its antibacterial activity has been widely concerned, but its antibacterial mechanism remains largely unknown. Protein leakage and the solution exosmosis conductivity of Bacillus subtilis 24434 (B. subtilis) reportedly display no noticeable differences before and after CGA treatment. The bacterial cells treated with CGA displayed a consistently smooth surface under the electron microscope, indicating that CGA cannot directly disrupt bacterial membranes. However, CGA induced a significant decrease in the intracellular adenosine triphosphate (ATP) concentration, possibly by affecting the material and energy metabolism or cell-signaling transduction. Furthermore, metabolomic results indicated that CGA stress had a bacteriostatic effect by inducing the intracellular metabolic imbalance of the tricarboxylic acid (TCA) cycle and glycolysis, leading to metabolic disorder and death of B. subtilis. These findings improve the understanding of the complex action mechanisms of CGA antimicrobial activity and provide theoretical support for the application of CGA as a natural antibacterial agent.

In order to improve the extraction ratio of rice bran oil, a single-factor experiment and response surface methodology with a central composite design were used to determine a new mixed solvent and the optimal extraction conditions of the mixed solvent. The effects of solid–liquid ratio, extraction time, extraction temperature, and oscillation speed on the extraction ratio were investigated. The regression equation was established, and the optimal extraction conditions were determined as follows: a solid–liquid ratio of 5.5:1, extraction temperature of 45 °C, extraction time of 12 min, and extraction ratio of rice bran oil of 85.8%. Compared with traditional solvent extraction, the peroxide value, acid value, iodine value, and fatty acid composition content of rice bran oil extracted using the new mixed solvent were close to those of n-hexane and significantly lower than those of solvent No. 6, while the content of oryzanol and total sterol increased to 2.7% and 5.1%. This study can be useful in exploring the possibility of new mixed solvents and provide theoretical guidance and data support for the production practice of new mixed solvents.

Rice’s geographic origin and variety play a vital role in commercial rice trade and consumption. However, a method for rapidly discriminating the geographical origins of rice from a different region is still lacking. Therefore, the current study developed a volatile organic compound (VOC) based geographical discrimination method using headspace gas chromatography-mass spectrometry (HS-GC-MS) to discriminate rice samples from Heilongjiang, Jilin, and Liaoning provinces. The rice VOCs in Heilongjiang, Liaoning, and Jilin were analyzed by agglomerative hierarchical clustering (AHC), principal component analysis (PCA), and partial least squares discriminant analysis (PLS-DA). The results show that the optimum parameters for headspace solid phase microextraction (HS-SPME) involved the extraction of 3.0 g of rice at 80 °C within 40 min. A total of 35 VOCs were identified from 30 rice varieties from Northeast China. The PLS-DA model exhibited good discrimination (R² = 0.992, Q² = 0.983, and Accuracy = 1.0) for rice samples from Heilongjiang, Liaoning, and Jilin. Moreover, K-nearest neighbors showed good specificity (100%) and accuracy (100%) in identifying the origin of samples. In conclusion, the present study established VOC fingerprinting as a highly efficient approach to identifying rice’s geographical origin. Our findings highlight the ability to discriminate rice from Heilongjiang, Liaoning, and Jilin provinces rapidly.

Slowing starch digestibility can delay or even prevent the occurrence and development of type 2 diabetes. To explore the hypoglycemic potential of highland barley polyphenols (HBP), this study investigated the structural characteristics and starch digestibility of individual or mixed HBP-starch complexes. The results showed that a V-type structure was formed in HBP-starch complexes through non-covalent bonds, resulting in a decrease in rapidly digestible starch and an increase in resistant starch. Specially, the compounding of HBP extracted by acetone significantly reduced the rapidly digestible starch content in amylose from 41.11% to 36.17% and increased the resistant starch content from 6.15% to 13.27% (p < 0.05). Moreover, due to different contents and types of monomer phenols, the HBP extracted with acetone were more effective in inhibiting starch digestion than those extracted with methanol. Ferulic acid and catechin were two key components of HBP. Further results indicated that with the increased content of ferulic acid and catechin (from 1% to 5%), they formed a more ordered structure with amylose, resulting in the lower digestibility of the complex. Collectively, this study suggested that highland barley polyphenols could effectively delay starch digestion by forming a more ordered starch crystal structure. Highland barley polyphenols can be used as functional ingredients in regulating the digestive properties of starchy foods.