CRISPR/Cas system has developed a new technology to modify target genes. In this study, CasΦ2 is a newly Cas protein that we used for genome modification in Arabidopsis and tobacco. PDS and BRI1 of marker genes were chosen for targeting. CasΦ2 has the function to cleave pre-crRNA. In the presence of 10 mM Mg²⁺ irons concentration, sgRNA3 type guided CasΦ2 to edit target gene and generate mutation, and a mutant seedling of AtBRI1 gene with an expected male sterile phenotype was obtained. In the process of tobacco transformation, the gene editing activity of CasΦ2 can be activated by 100 nM Mg²⁺ irons concentration, and sgRNA1 type guided CasΦ2 to edit target gene. Mutant seedlings of NtPDS gene with an expected albino were obtained. The results indicate that CasΦ2 can effectively edit target genes under the guidance of different sgRNA type in the presence of Mg²⁺ ions. Together, our results verify that the CRISPR/CasΦ2 system is an effective and precise tool for genome editing in plants.

Background: Drought stress is a serious threat that limit maize growth and production.Objectives: The assessment tolerance level of maize by measuring changes in the main biochemical and physiological indicators under drought stress.Material and Methods: We performed a genome-wide association analysis of biochemical and physiological indicators using an elite association panel.Results: The results revealed that eight significant SNPs (p<0.05/N) located in eight genes that are distributed on different chromosomes were associated with drought resistance indices under drought stress. Among these genes, four genes were linked via the associated SNPs with drought-resistance indices of the malondialdehyde activity (MDA), three genes were linked with drought resistance indexes of the superoxide dismutase activity (SOD), and one gene was linked with drought resistance indexes of relative conductivity (REC). The candidate genes functioned as transcription factors, enzymes, and transporters, which included trehalase, the AP2/EREB160 transcription factor, and glutathione S-transferase and also encoded a gene of unknown function. These genes may be directly or indirectly involved in drought resistance. The expression levels of ZmEREB160 responded to ABA and drought stress.Conclusions: These results provided good information to understand the genetic basis of variation in drought resistance indices of biochemical and physiological indicators during drought stress.

Tropical ornamental Anthurium andraeanum requires substantial electrical heating for overwintering when cultivated in greenhouses in subtropical regions, making cold tolerance improvement a key factor for cost reduction. However, whether exogenous 6-Benzylaminopurine (6-BA) can enhance cold hardiness in Anthurium and its underlying mechanisms remain unclear. In this study, we conducted a controlled experiment to compare the physiological and biochemical responses of A. andraeanum ‘Alabama’ subjected to low-temperature stress following foliar application of 6-BA versus water. Our results show that, compared with water treatment, 6-BA application was associated with better preservation of subcellular structural integrity, higher proline accumulation, lower hydrogen peroxide content, decreased relative electrical conductivity, increased leaf fresh weight, dry weight, and area along with reduced water content, and lower stomatal density. These findings suggest that, under defined low-temperature conditions, 6-BA is associated with enhanced physiological performance in A. andraeanum, potentially through coordinated effects on subcellular stability, osmotic adjustment, reactive oxygen species accumulation, leaf morphology and water metabolism, and stomatal density. This work provides a theoretical basis and technical reference for cold-tolerant cultivation of Anthurium.