Comprehensive identification and expression analysis of CRY gene family in Gossypium

Seed priming with graphene oxide improves salinity tolerance and increases productivity of peanut through modulating multiple physiological processes

Graphene oxide (GO), beyond its specialized industrial applications, is rapidly gaining prominence as a nanomaterial for modern agriculture. However, its specific effects on seed priming for salinity tolerance and yield formation in crops remain elusive. Under both pot-grown and field-grown conditions, this study combined physiological indices with transcriptomics and metabolomics to investigate how GO affects seed germination, seedling salinity tolerance, and peanut pod yield. Peanut seeds were firstly treated with 400 mg L⁻¹ GO (termed GO priming). At seed germination stage, GO-primed seeds exhibited higher germination rate and percentage of seeds with radicals breaking through the testa. Meanwhile, omics analyses revealed significant enrichment in pathways associated with carbon and nitrogen metabolisms in GO-primed seeds. At seedling stage, GO priming contributed to strengthening plant growth, enhancing photosynthesis, maintaining the integrity of plasma membrane, and promoting the nutrient accumulation in peanut seedlings under 200 mM NaCl stress. Moreover, GO priming increased the activities of antioxidant enzymes, along with reduced the accumulation of reactive oxygen species (ROS) in response to salinity stress. Furthermore, the differentially expressed genes (DEGs) and differentially accumulated metabolites (DAMs) of peanut seedlings under GO priming were mainly related to photosynthesis, phytohormones, antioxidant system, and carbon and nitrogen metabolisms in response to soil salinity. At maturity, GO priming showed an average increase in peanut pod yield by 12.91% compared with non-primed control. Collectively, our findings demonstrated that GO plays distinguish roles in enhancing seed germination, mitigating salinity stress, and boosting pod yield in peanut plants via modulating multiple physiological processes.

AaMYC3 bridges the regulation of glandular trichome density and artemisinin biosynthesis in Artemisia annua

Artemisinin, the well-known natural product for treating malaria, is biosynthesised and stored in the glandular-secreting trichomes (GSTs) of Artemisia annua. While numerous efforts have clarified artemisinin metabolism and regulation, the molecular association between artemisinin biosynthesis and GST development remains elusive. Here, we identified AaMYC3, a bHLH transcription factor of A. annua, induced by jasmonic acid (JA), which simultaneously regulates GST density and artemisinin biosynthesis. Overexpressing AaMYC3 led to a substantial increase in GST density and artemisinin accumulation. Conversely, in the RNAi-AaMYC3 lines, both GST density and artemisinin content were markedly reduced. Through RNA-seq and analyses conducted both in vivo and in vitro, AaMYC3 not only directly activates AaHD1 transcription, initiating GST development, but also up-regulates the expression of artemisinin biosynthetic genes, including CYP71AV1 and ALDH1, thereby promoting artemisinin production. Furthermore, AaMYC3 acts as a co-activator, interacting with AabHLH1 and AabHLH113, to trigger the transcription of two crucial enzymes in the artemisinin biosynthesis pathway, ADS and DBR2, ultimately boosting yield. Our findings highlight a critical connection between GST initiation and artemisinin biosynthesis in A. annua, providing a new target for molecular design breeding of traditional Chinese medicine.

Comparative Genomics and Functional Studies of Putative m6A Methyltransferase (METTL) Genes in Cotton

N6-methyladenosine (m6A) RNA modification plays important regulatory roles in plant development and adapting to the environment, which requires methyltransferases to achieve the methylation process. However, there has been no research regarding m6A RNA methyltransferases in cotton. Here, a systematic analysis of the m6A methyltransferase (METTL) gene family was performed on twelve cotton species, resulting in six METTLs identified in five allotetraploid cottons, respectively, and three to four METTLs in the seven diploid species. Phylogenetic analysis of protein-coding sequences revealed that METTL genes from cottons, Arabidopsis thaliana, and Homo sapiens could be classified into three clades (METTL3, METTL14, and METTL-like clades). Cis-element analysis predicated the possible functions of METTL genes in G. hirsutum. RNA-seq data revealed that GhMETTL14 (GH_A07G0817/GH_D07G0819) and GhMETTL3 (GH_A12G2586/GH_D12G2605) had high expressions in root, stem, leaf, torus, petal, stamen, pistil, and calycle tissues. GhMETTL14 also had the highest expression in 20 and 25 dpa fiber cells, implying a potential role at the cell wall thickening stage. Suppressing GhMETTL3 and GhMETTL14 by VIGS caused growth arrest and even death in G. hirsutum, along with decreased m6A abundance from the leaf tissues of VIGS plants. Overexpression of GhMETTL3 and GhMETTL14 produced distinct differentially expressed genes (DEGs) in A. thaliana, indicating their possible divergent functions after gene duplication. Overall, GhMETTLs play indispensable but divergent roles during the growth of cotton plants, which provides the basis for the systematic investigation of m6A in subsequent studies to improve the agronomic traits in cotton.

TRY intron2 determined its expression in inflorescence activated by SPL9 and MADS-box genes in Arabidopsis

Plant trichomes are specialized epidermal cells that protect plants from insects and pathogens. In Arabidopsis, epidermal hairs decrease as internodes increase in height, with only few epidermal hairs produced on the sepals abaxial surface of the early flowers. TRIPTYCHON (TRY) is known to be a negative regulator of epidermal hair development in Arabidopsis, suppressing the formation of ectopic epidermal hairs in the inflorescence. Here, we reported that the second intron of TRY gene plays a critical role in trichome spatial distribution in Arabidopsis. The expression of TRY rises with the increasing stem nodes and reaches the peak in the inflorescence, while the trichomes distribution decrease. The transgenic plants showed that TRY promoter could only drive the genomic instead of coding sequences combined with GUS reporter gene, which indicates that the regulatory elements of TRY expression in inflorescence could be located in the intron regions. Multiple SPLs and MADS-box binding sites were found in the TRY intron2 sequence. Further genetic and biochemistry assays revealed that the flowering-related genes such as SPL9 could bind to these cis-elements directly, contributing to the TRY spatial expression. Since cotton fiber and Arabidopsis trichomes share similar regulatory mechanism, extended analysis showed that the intron2 of cotton TRY genes also contain the cis-elements. Thus, the introns harboring the transcription element may be the general way to regulate the gene expression in different plants and provides molecular clues for the related crops' traits design.

Systematical characterization of GRF gene family in sorghum, and their potential functions in aphid resistance

Sorghum (Sorghum bicolor) is the fifth important cereal and an industrial energy crop in the world. Growth Regulation Factors (GRFs) play an important role in response to environmental stress, however, the knowledge of GRFs relating to the pest resistance is lacking. Here, we identified 8 GRF genes harboring the typical QLQ (glutamine, leucine, glutamine) and WRC (tryptophan, arginine, cysteine) domains in Sorghum, which could be classified into 4 clades through phylogenetic analysis. The SbGRF genes express in most tissues, while more than half of them express at the highest level in inflorescence. To further investigate their possible role in stress response, we analyzed the transcriptomics data. The results showed that SbGRFs could respond to the abiotic stresses including heat, salt and drought stress. Furthermore, combined the data with qRT-PCR, SbGRF1, 2, 4 and 7 were identified as dominant genes response to the aphid-induced stress. SSR markers close to these genes were also searched. Above all, we summarized the SbGRFs and provided their potential roles in aphid response.