Overexpression of pPLAIIIγ in Arabidopsis Reduced Xylem Lignification of Stem by Regulating Peroxidases

Overexpression of the patatin-related phospholipase A gene, PgpPLAIIIβ, in ginseng adventitious roots reduces lignin and ginsenoside content while increasing fatty acid content

The patatin-related phospholipase AIII (pPLAIII) gene family plays a crucial role in regulating cell elongation, cell wall composition, and lipid metabolism in plants, making it a promising target for agricultural and commercial innovations. This study provides a comprehensive functional analysis of PgpPLAIIIβ in Panax ginseng, a medicinal plant of substantial economic importance. Overexpression of PgpPLAIIIβ led to significant morphological changes, including shorter, thicker roots, and an 8% reduction in lignin content, while cellulose levels remained unaffected. The reduced lignification was attributed to the downregulation of key lignin biosynthetic genes and decreased hydrogen peroxide accumulation. A yeast two-hybrid assay identified a CCCH-type zinc finger protein as a potential PgpPLAIIIβ interactor, pointing to a mechanism that may underlie the changes in root structure and lignin deposition. Metabolite analysis revealed a 7.6% increase in total free fatty acid content, with notable increases in palmitic and linoleic acids, alongside a 28% reduction in ginsenoside levels, linked to the downregulation of triterpenoid biosynthetic genes. These findings demonstrate that PgpPLAIIIβ is a key regulator of root architecture, lignin composition, and secondary metabolite balance in ginseng. The metabolic engineering of PgpPLAIIIβ could be a powerful strategy to improve root traits, optimize lignin deposition, and enhance metabolite profiles, ultimately boosting the commercial and medicinal value of ginseng.

A group III patatin-like phospholipase gene pPLAIIIδ regulates lignin biosynthesis and influences the rate of seed germination in Arabidopsis thaliana

The lignification of plant secondary walls is an important process that provides plants with mechanical support. However, the presence of lignin in the secondary walls affects the readily availability of cellulose required in various industries, including the biofuel, paper, and textile industries. Thus, plants with less lignin are ideal for usage in such industries. Molecular studies have identified genes that regulate plant lignification, including group III plant-specific patatin-related phospholipase genes. Recent studies have reported decreased lignin content when pPLAIIIα, pPLAIIIγ (from Arabidopsis thaliana), and pPLAIIIβ (from Panax ginseng) were overexpressed in Arabidopsis. However, the role played by a closely related gene pPLAIIIδ in lignin biosynthesis has not yet been reported. In this study, we found that overexpression of the pPLAIIIδ significantly reduced the lignin content in secondary cell walls, whereas the silencing of the gene increased secondary walls lignification. Transcript level analysis showed that the key structural and regulatory genes involved in the lignin biosynthesis pathway decreased in overexpression, and increased in plants with silenced pPLAIIIδ. Further analysis revealed that pPLAIIIδ played an influential role in several physiological processes including seed germination, and chlorophyll accumulation. Moreover, the gene also influenced the size of plants and plant organs, including leaves, seeds, and root hairs. Generally, our study provides important insights toward the use of genetic engineering for lignin reduction in plants and provides information about the agronomical and physiological suitability of pPLAIIIδ transgenic plants for utilization in biomass processing industries.

Loss-of-function of gynoecium-expressed phospholipase pPLAIIγ triggers maternal haploid induction in Arabidopsis

Production of in planta haploid embryos that inherit chromosomes from only one parent can greatly increase breeding efficiency via quickly generating homozygous plants, called doubled haploid. One of the main players of in planta haploid induction is a pollen-specific phospholipase A, which is able, when mutated, to induce in vivo haploid induction in numerous monocots. However, no functional orthologous gene has been identified in dicots plants. Here, we show that loss-of-function of gynoecium-expressed phospholipase AII (pPLAIIγ) triggers maternal haploid plants in Arabidopsis, at an average rate of 1.07%. Reciprocal crosses demonstrate that haploid plants are triggered from the female side and not from the pollen, and the haploid plants carry the maternal genome. Promoter activity of pPLAIIγ shows enriched expression in the funiculus of flower development stages 13 and 18, and pPLAIIγ fused to yellow fluorescent protein reveals a plasma-membrane localization Interestingly, the polar localized PIN1 at the basal plasma membrane of the funiculus was all internalized in pplaIIγ mutants, suggesting that altered PIN1 localization in female organ could play a role in maternal haploid induction.

Understanding Cannabis sativa L.: Current Status of Propagation, Use, Legalization, and Haploid-Inducer-Mediated Genetic Engineering

Cannabis sativa L. is an illegal plant in many countries. The worldwide criminalization of the plant has for many years limited its research. Consequently, understanding the full scope of its benefits and harm became limited too. However, in recent years the world has witnessed an increased pace in legalization and decriminalization of C. sativa. This has prompted an increase in scientific studies on various aspects of the plant’s growth, development, and use. This review brings together the historical and current information about the plant’s relationship with mankind. We highlight the important aspects of C. sativa classification and identification, carefully analyzing the supporting arguments for both monotypic (single species) and polytypic (multiple species) perspectives. The review also identifies recent studies on suitable conditions and methods for C. sativa propagation as well as highlighting the diverse uses of the plant. Specifically, we describe the beneficial and harmful effects of the prominent phytocannabinoids and provide status of the studies on heterologous synthesis of phytocannabinoids in different biological systems. With a historical view on C. sativa legality, the review also provides an up-to-date worldwide standpoint on its regulation. Finally, we present a summary of the studies on genome editing and suggest areas for future research.