TrichomeLess Regulator 3 is required for trichome initial and cuticle biosynthesis in Artemisia annua.

Artemisinin is primarily synthesized and stored in the subepidermal space of the glandular trichomes of Artemisia annua. The augmentation of trichome density has been demonstrated to enhance artemisinin yield. However, existing literature lacks insights into the correlation between the stratum corneum and trichomes. This study aims to unravel the involvement of TrichomeLess Regulator 3 (TLR3), which encodes the transcription factor, in artemisinin biosynthesis and its potential association with the stratum corneum. TLR3 was identified as a candidate gene through transcriptome analysis. The role of TLR3 in trichome development and morphology was investigated using yeast two-hybrid, pull-down analysis, and RNA electrophoresis mobility assay. Our research revealed that TLR3 negatively regulates trichome development. It modulates the morphology of Arabidopsis thaliana trichomes by inhibiting branching and inducing the formation of abnormal trichomes in Artemisia annua. Overexpression of the TLR3 gene disrupts the arrangement of the stratum corneum and reduces artemisinin content. Simultaneously, TLR3 possesses the capacity to regulate stratum corneum development and trichome follicle morphology by interacting with TRICHOME AND ARTEMISININ REGULATOR 1, and CycTL. Consequently, our findings underscore the pivotal role of TLR3 in the development of glandular trichomes and stratum corneum biosynthesis, thereby influencing the morphology of Artemisia annua trichomes.

AaWRKY6 contributes to artemisinin accumulation during growth in Artemisia annua.

Artemisinin, which is extracted from the plant Artemisia annua L., is a crucial drug for curing malaria and has potential applications for treating cancer, diabetes, pulmonary tuberculosis, and other conditions. Demand for artemisinin is therefore high, and enhancing its yield is important. Artemisinin dynamics change during the growth cycle of A. annua; however, the regulatory networks underlying these changes are poorly understood. Here, we collected A. annua leaves at different growth stages and identified target genes from transcriptome data. We determined that WRKY6 binds to the promoters of the artemisinin biosynthesis gene artemisinic aldehyde Δ11(13) reductase (DBR2). In agreement, overexpression of WRKY6 in A. annua resulted in higher expression levels of genes in the artemisinin biosynthesis pathway and greater artemisinin contents than in the wild type. When expression of WRKY6 was down-regulated, artemisinin biosynthesis pathway genes were also down-regulated and the content of artemisinin was lower. WRKY6 mediates the transcriptional activation of artemisinin biosynthesis by binding to the promoter of DBR2, making it a key regulator for modulating the dynamics of artemisinin changes during the A. annua growth cycle.

Mutational Bias and Natural Selection Driving the Synonymous Codon Usage of Single-Exon Genes in Rice (Oryza sativa L.).

The relative abundance of single-exon genes (SEGs) in higher plants is perplexing. Uncovering the synonymous codon usage pattern of SEGs will benefit for further understanding their underlying evolutionary mechanism in plants. Using internal correspondence analysis (ICA), we reveal a significant difference in synonymous codon usage between SEGs and multiple-exon genes (MEGs) in rice. But the effect is weak, accounting for only 2.61% of the total codon usage variability. SEGs and MEGs contain remarkably different base compositions, and are under clearly differential selective constraints, with the former having higher GC content, and evolving relatively faster during evolution. In the group of SEGs, the variability in synonymous codon usage among genes is partially due to the variations in GC content, gene function, and gene expression level, which accounts for 22.03%, 5.99%, and 3.32% of the total codon usage variability, respectively. Therefore, mutational bias and natural selection should work on affecting the synonymous codon usage of SEGs in rice. These findings may deepen our knowledge for the mechanisms of origination, differentiation and regulation of SEGs in plants.

Strategic nanoparticle-mediated plant disease resistance.

Nanotechnology is a promising means for development of sustainable agriculture while the study of nanoparticle-mediated plant disease resistance is still in its primary stage. Nanotechnology has shown great promise in regulating: the content of secondary metabolites, inducing disease resistance genes, delivering hormones, delivering biomolecules (such as: nucleotides, proteins, and activators), and obtaining transgenic plants to resist plant diseases. In this review, we conclude its versatility and applicability in disease management strategies and diagnostics and as molecular tools. With the advent of new biotechnologies (e.g. de novo regeneration, CRISPR/Cas9, and GRF4-GIF1 fusion protein), we discuss the potential of nanoparticles as an optimal platform to deliver biomolecules to plants for genetic engineering. In order to ensure the safe use and social acceptance of plant nanoparticle technology, its adverse effects are discussed, including the risk of transferring nanoparticles through the food chain.

Phytohormone-Based Regulation of Trichome Development.

Phytohormones affect plant growth and development. Many phytohormones are involved in the initiation of trichome development, which can help prevent damage from UV radiation and insect bites and produce fragrance, flavors, and compounds used as pharmaceuticals. Phytohormones promote the participation of transcription factors in the initiation of trichome development; for example, the transcription factors HDZIP, bHLH and MYB interact and form transcriptional complexes to regulate trichome development. Jasmonic acid (JA) mediates the progression of the endoreduplication cycle to increase the number of multicellular trichomes or trichome size. Moreover, there is crosstalk between phytohormones, and some phytohormones interact with each other to affect trichome development. Several new techniques, such as the CRISPR-Cas9 system and single-cell transcriptomics, are available for investigating gene function, determining the trajectory of individual trichome cells and elucidating the regulatory network underlying trichome cell lineages. This review discusses recent advances in the modulation of trichome development by phytohormones, emphasizes the differences and similarities between phytohormones initially present in trichomes and provides suggestions for future research.

AaCycTL Regulates Cuticle and Trichome Development in Arabidopsis and Artemisia annua L.

Artemisinin is an important drug for resistance against malaria. Artemisinin is derived from the glandular trichome of leaves, stems, or buds of the Chinese traditional herb Artemisia annua. Increasing the trichome density may enhance the artemisinin content of A. annua. It has been proven that cyclins are involved in the development of trichomes in tomato, Arabidopsis, and tobacco, but it is unclear whether the cyclins in A. annua influence trichome development. In this study, we showed that AaCycTL may regulate trichome development and affect the content of artemisinin. We cloned AaCycTL and found that it has the same expression files as the artemisinin biosynthesis pathway gene. We overexpressed AaCycTL in Arabidopsis, and the results indicated that AaCycTL changed the wax coverage on the surface of Arabidopsis leaves. The trichome density decreased as well. Using yeast two-hybrid and BiFC assays, we show that AaCycTL can interact with AaTAR1. Moreover, we overexpressed AaCycTL in A. annua and found that the expression of AaCycTL was increased to 82-195%. Changes in wax coverage on the surface of transgenic A. annua leaves or stems were found as well. We identified the expression of the artemisinin biosynthesis pathway genes ADS, CYP71AV1, and ALDH1 has decreased to 88-98%, 76-97%, and 82-97% in the AaCycTL-overexpressing A. annua lines, respectively. Furthermore, we found reduced the content of artemisinin. In agreement, overexpression of AaCycTL in A. annua or Arabidopsis may alter waxy loading, change the initiation of trichomes and downregulate trichome density. Altogether, AaCycTL mediates trichome development in A. annua and thus may serve to regulate trichome density and be used for artemisinin biosynthesis.

INHIBIT-inspired two-output DNA logic gates based on surface-enhanced Raman scattering.

Herein, we presented a novel logic gate based on an INHIBITION gate that performs parallel readouts. Logic gates performing INHIBITION and YES/OR were constructed using surface-enhanced Raman scattering as optical outputs for the first time. The strategy allowed for simultaneous reading of outputs in one tube. The applicability of this strategy has been successfully exemplified in the construction of half-adder using the two-output logic gates as reporting gates. This reporting strategy provides additional design flexibility for dynamic DNA devices.

Toehold-mediated DNA logic gates based on host-guest DNA-GNPs.

A simple, toehold-mediated two-way input DNA machine has been developed. Utilizing symmetric and asymmetric protector sequences, INH, XOR logic gates and a half-subtractor are designed based on this two-way structure.