Zhaoqun Yao

Cotton damping-off caused by Rhizoctonia solani restricts seedling establishment, and locally adapted biocontrol isolates are potential components of sustainable disease management. This study evaluated Pseudomonas chlororaphis-like isolate M6 and tested whether molecular profiles in M6-protected plants differed from those in Pathogen-infected plants in directions that moved toward Healthy Control levels. Culturable bacteria from root-associated soils were screened against R. solani by dual-culture assays, and M6 was evaluated in a greenhouse cotton damping-off assay. RNA sequencing (RNA-seq) and untargeted liquid chromatography–mass spectrometry (LC–MS) data from Healthy Control, Pathogen-infected, and M6-protected plants at 0 and 7 d were analyzed using the Pathogen-infected versus Healthy Control and M6-protected versus Pathogen-infected contrasts. M6 produced the highest inhibition among the candidate isolates (81.9%). Under greenhouse conditions, the M6-protected treatment had lower disease incidence (22.2% versus 88.9%) and disease index (16.4 versus 76.8) than the Pathogen-infected treatment. At 7 d, the primary false-discovery-rate-controlled analysis identified 4457 transcripts and 1620 LC–MS features for which the change between M6-protected and Pathogen-infected plants was opposite to the pathogen-associated change and the M6-protected group mean was closer to the Healthy Control mean. Additional nominal-p-value-only results were retained as exploratory. The two contrasts involved redox regulation, phenylpropanoid/benzenoid-related metabolism, hormone/defense signaling, protein synthesis and central metabolism. Antioxidant enzyme and quantitative reverse transcription PCR (qRT-PCR) data provided independent support for selected redox- and defense-associated differences. Because pathogen biomass, bacterial colonization and antagonism-deficient mutants were not assessed, the molecular profiles are interpreted as association-based features of the protected state rather than evidence that host recovery caused disease reduction. Most LC–MS annotations are putative and were not confirmed with authentic standards.

Phelipanche aegyptiaca , a root holoparasitic weed, severely threatens agricultural productivity due to its detrimental effects. This species relies on a specialised organ, namely the haustorium, to extract nutrients from its host plants. The germination and haustorium formation of P. aegyptiaca are initiated by sensing host plant root exudates. Differences in exudate composition are crucial markers of host resistance. Host plant root exudates significantly influence the development and survival of P. aegyptiaca . To identify root exudates affecting the parasitic weed's growth, we analysed differential metabolites in resistant and susceptible Cucumis melo varieties. Among these, 6‐hydroxynicotinic acid was identified as a key compound. Prehaustorium formation, which is induced by haustorium‐inducing factors, such as indole‐3‐acetic acid (IAA), was suppressed in the presence of 6‐hydroxynicotinic acid. This compound exerts an inhibitory effect by reducing the expression of genes related to the auxin signalling pathway of P. aegyptiaca , thus weakening parasitism. Our results support a model in which 6‐hydroxynicotinic acid inhibits prehaustorium development in P. aegyptiaca by disrupting gene expression and endogenous metabolism.

Introduction: Verticillium wilt, caused by Verticillium dahliae, is one of the most devastating diseases affecting global cotton (Gossypium hirsutum) production. Given the limited effectiveness of chemical control measures and the polygenic nature of resistance, elucidating the key genetic determinants is imperative for the development of resistant cultivars. In this study, we aimed to dissect the temporal transcriptional dynamics and regulatory mechanisms underlying Gossypium hirsutum response to V. dahliae infection.Methods: We employed a time-course RNA-Seq approach using the susceptible upland cotton cultivar Jimian 11 to profile transcriptomic responses in root and leaf tissues post-V. dahliae inoculation. Differentially expressed genes (DEGs) were identified, followed by weighted gene co-expression network analysis (WGCNA). To prioritize key candidate genes, we applied machine learning algorithms including LASSO, Random Forest, and Support Vector Machine (SVM).Results and discussion: A robust set of core genes involved in pathogen recognition (GhRLP6), calcium signaling (GhCIPK6, GhCBP60A), hormone response, and secondary metabolism (GhF3’H) were identified. Our findings provide novel insights into the spatiotemporal regulation of immune responses in cotton and offer valuable candidate genes for molecular breeding of Verticillium wilt resistance.

Phelipanche aegyptiaca is an obligate root-parasitic weed that parasitizes crop roots, threatening the safety of agricultural production. However, the molecular mechanisms underlying the formation of P. aegyptiaca haustorium remain largely unclear. Here, we employed transcriptomics to investigate the molecular events in P. aegyptiaca haustorium formation induced by indole-3-acetic acid. Our study revealed that during P. aegyptiaca haustorium formation, the cell proliferation activity at the tip of the radicle was highest during the young stage and then gradually declined. The differentially expressed genes upregulated during haustorium formation were mainly enriched in DNA replication and plant hormone signal transduction, while those that were downregulated were enriched in biosynthesis of secondary metabolites. Additionally, interfering with the auxin signal weakened the parasitic ability of P. aegyptiaca. These findings enhance our understanding of the mechanism of P. aegyptiaca haustorium formation and contribute to the targeted development of new pesticides for inhibiting P. aegyptiaca.

The electrocatalytic carbon dioxide reduction reaction (CO₂RR) is a promising approach to achieving a sustainable carbon cycle. Recently, diatomic catalysts (DACs) have demonstrated advantages in the CO₂RR due to their complex and flexible active sites. However, our understanding of how DACs break the scaling relationship remains insufficient. Here, we investigate the CO₂RR of 465 kinds of graphene-based DACs (M1M2-N6@Gra) formed from 30 metal atoms through high-throughput density functional theory (DFT) calculations. We find that the intermediates *COOH, *CO, and *CHO have multiple adsorption states, with 11 structural flow directions from *CO to *CHO. Four of these structural flow directions have catalysts that can break the linear scale relationship. Based on the adsorption energy relationship between *COOH, *CHO and *CO, we propose the concepts of linear scaling, moderate breaking, and severe deviation regions, leading to the establishment of new descriptors that identify 14 catalysts with potential superior performance. Among them, ZnRu-N6@Gra and CrNi-N6@Gra can reduce CO₂ to CH₄ at a low limiting potential. We also discovered that DACs have independent bidirectional electron transfer channels during the adsorption and activation of CO₂, which can significantly improve the flexibility and efficiency of regulating the electronic structure. Furthermore, through machine learning (ML) analysis, we identify electronegativity, atomic number, and d electron count as key determinants of catalyst stability. This work provides new insights into the understanding of the DAC catalytic mechanism, as well as the design and screening of catalysts.

The efficient protoplast transient transformation system in plants is an important tool to study gene expression, metabolic pathways, and various mutagenic parameters, but it has not been established in Phelipanche aegyptiaca. As a root parasitic weed that endangers the growth of 29 species of plants in 12 families around the world, there is still no good control method for P. aegyptiaca. Even the parasitic mechanisms of P. aegyptiaca and the related genes regulating parasitism are not yet understood. In this study, by comparing the factors related to protoplast isolation and transfection, we developed the optimal protocol for protoplast isolation and transfection in Phelipanche aegyptiaca haustorium. The optimal protoplast yield and activity were 6.2 × 10⁶ protoplasts/g fresh weight [FW] and 87.85%, respectively, by using 0.5 mol/L mannitol, enzyme concentrations of 2.5% cellulase R-10 and 0.8% Macerozyme R-10 at 24 °C for 4 h. At the same time, transfection efficiency of protoplasts was up to 78.49% when using 30 μg plasmid, 40% polyethylene glycol (PEG) concentration, 24 °C incubation temperature, and 20 min transfection time. This is the first efficient protoplasts’ isolation and transient transformation system of Phelipanche aegyptiaca haustorium, laying a foundation for future studies on the gene function and mechanisms of haustorium formation in parasitic plants.

Phelipanche aegyptiaca can infect many crops, causing large agricultural production losses. It is important to study the parasitism mechanism of P. aegyptiaca to control its harm. In this experiment, the P. aegyptiaca HY13M and TE9M from Tacheng Prefecture and Hami City in Xinjiang, respectively, were used to analyze the parasitical mechanism of P. aegyptiaca by means of transcriptome and proteome analyses. The parasitic capacity of TE9M was significantly stronger than that of HY13M in Citrullus lanatus. The results showed that the DEGs and DEPs were prominently enriched in the cell wall metabolism pathways, including “cell wall organization or biogenesis”, “cell wall organization”, and “cell wall”. Moreover, the functions of the pectinesterase enzyme gene (TR138070_c0_g), which is involved in the cell wall metabolism of P. aegyptiaca in its parasitism, were studied by means HIGS. The number and weight of P. aegyptiaca were significantly reduced when TR138070_c0_g1, which encodes a cell-wall-degrading protease, was silenced, indicating that it positively regulates P. aegyptiaca parasitism. Thus, these results suggest that the cell wall metabolism pathway is involved in P. aegyptiaca differentiation of the parasitic ability and that the TR138070_c0_g1 gene plays an important role in P. aegyptiaca’s parasitism.

Coleus (Plectranthus scutellarioides [L.] R.Br., [syn.: Solenostemon scutellarioides], Lamiaceae) is a popular ornamental plant for its colorful and showy foliage, and widely planted as a garden pl...

Coleus (Plectranthus scutellarioides [L.] R.Br.[syn.: Solenostemon scutellarioides]) is a perennial plant in the Lamiaceae family. It produces variegated leaves of various colors. It is commonly cu...

Phelipanche aegyptiaca is one of the most destructive root parasitic plants of Orobanchaceae. This plant has significant impacts on crop yields worldwide. Conditioned and host root stimulants, in particular, strigolactones, are needed for unique seed germination. However, no extensive study on this phenomenon has been conducted because of insufficient genomic information. Deep RNA sequencing, including de novo assembly and functional annotation was performed on P. aegyptiaca germinating seeds. The assembled transcriptome was used to analyze transcriptional dynamics during seed germination. Key gene categories involved were identified. A total of 274,964 transcripts were determined, and 53,921 unigenes were annotated according to the NR, GO, COG, KOG, and KEGG databases. Overall, 5324 differentially expressed genes among dormant, conditioned, and GR24-treated seeds were identified. GO and KEGG enrichment analyses demonstrated numerous DEGs related to DNA, RNA, and protein repair and biosynthesis, as well as carbohydrate and energy metabolism. Moreover, ABA and ethylene were found to play important roles in this process. GR24 application resulted in dramatic changes in ABA and ethylene-associated genes. Fluridone, a carotenoid biosynthesis inhibitor, alone could induce P. aegyptiaca seed germination. In addition, conditioning was probably not the indispensable stage for P. aegyptiaca, because the transcript level variation of MAX2 and KAI2 genes (relate to strigolactone signaling) was not up-regulated by conditioning treatment.