Identification of the CDPK gene family in patchouli and functional analysis in response to continuous cropping stress.

To further reveal the molecular mechanisms underlying the formation of continuous cropping disorders in patchouli, this study analyzed the function of calcium dependent protein kinase (CDPK) genes at the molecular level in patchouli continuous cropping disorders. The findings unveiled the presence of 45 PcCDPK genes within the complete patchouli genome dataset. These genes exhibited a range of molecular weights from 50.78 to 78.96 kDa and aliphatic index values spanning from 74.42 to 88.49, and are shown to be hydrophilic proteins. The evolution of 45 PcCDPK members was divided into 4 subfamilies, with a total of 65 pairs of collinear genes. Each PcCDPK contains a STKc-CAMK domain and four EF-hand structures exhibiting a certain degree of conservatism during evolution. Transcriptome data further supported the significance of PcCDPK25 and PcCDPK38 genes, showing substantial upregulation, which was corroborated by qRT-PCR results. The 1629 bp and 1716 bp CDS sequences were obtained by cloning the PcCDPK25 and PcCDPK38 genes, respectively, and subcellular localization showed that both proteins were localized on the plasma membrane. This comprehensive study provides molecular-level confirmation of the pivotal roles played by CDPK genes in the emergence of continuous cropping challenges in patchouli plants, establishing a crucial foundation for a deeper comprehension of the molecular mechanisms underpinning these obstacles.

A Genome-Wide Identification and Expression Analysis of the Casparian Strip Membrane Domain Protein-like Gene Family in Pogostemon cablin in Response to p-HBA-Induced Continuous Cropping Obstacles.

Casparian strip membrane domain protein-like (CASPL) genes are key genes for the formation and regulation of the Casparian strip and play an important role in plant abiotic stress. However, little research has focused on the members, characteristics, and biological functions of the patchouli PatCASPL gene family. In this study, 156 PatCASPL genes were identified at the whole-genome level. Subcellular localization predicted that 75.6% of PatCASPL proteins reside on the cell membrane. A phylogenetic analysis categorized PatCASPL genes into five subclusters alongside Arabidopsis CASPL genes. In a cis-acting element analysis, a total of 16 different cis-elements were identified, among which the photo-responsive element was the most common in the CASPL gene family. A transcriptome analysis showed that p-hydroxybenzoic acid, an allelopathic autotoxic substance, affected the expression pattern of PatCASPLs, including a total of 27 upregulated genes and 30 down-regulated genes, suggesting that these PatCASPLs may play an important role in the regulation of patchouli continuous cropping obstacles by affecting the formation and integrity of Casparian strip bands. These results provided a theoretical basis for exploring and verifying the function of the patchouli PatCASPL gene family and its role in continuous cropping obstacles.

A Systematic Review on the Continuous Cropping Obstacles and Control Strategies in Medicinal Plants.

Continuous cropping (CC) is a common practice in agriculture, and usually causes serious economic losses due to soil degeneration, decreased crop yield and quality, and increased disease incidence, especially in medicinal plants. Continuous cropping obstacles (CCOs) are mainly due to changes in soil microbial communities, nutrient availability, and allelopathic effects. Recently, progressive studies have illustrated the molecular mechanisms of CCOs, and valid strategies to overcome them. Transcriptomic and metabolomics analyses revealed that identified DEGs (differently expressed genes) and metabolites involved in the response to CCOs are involved in various biological processes, including photosynthesis, carbon metabolism, secondary metabolite biosynthesis, and bioactive compounds. Soil improvement is an effective strategy to overcome this problem. Soil amendments can improve the microbial community by increasing the abundance of beneficial microorganisms, soil fertility, and nutrient availability. In this review, we sum up the recent status of the research on CCOs in medicinal plants, the combination of transcriptomic and metabolomics studies, and related control strategies, including uses of soil amendments, crop rotation, and intercropping. Finally, we propose future research trends for understanding CCOs, and strategies to overcome these obstacles and promote sustainable agriculture practices in medicinal plants.