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Background Plant health and growth are negatively affected by pathogen invasion; however, plants can dynamically modulate their rhizosphere microbiome and adapt to such biotic stresses. Although plant-recruited protective microbes can be assembled into synthetic communities for application in the control of plant disease, rhizosphere microbial communities commonly contain some taxa at low abundance. The roles of low-abundance microbes in synthetic communities remain unclear; it is also unclear whether all the microbes enriched by plants can enhance host adaptation to the environment. Here, we assembled a synthetic community with a disease resistance function based on differential analysis of root-associated bacterial community composition. We further simplified the synthetic community and investigated the roles of low-abundance bacteria in the control of Astragalus mongholicus root rot disease by a simple synthetic community. Results Fusarium oxysporum infection reduced bacterial Shannon diversity and significantly affected the bacterial community composition in the rhizosphere and roots of Astragalus mongholicus . Under fungal pathogen challenge, Astragalus mongholicus recruited some beneficial bacteria such as Stenotrophomonas , Achromobacter , Pseudomonas , and Flavobacterium to the rhizosphere and roots. We constructed a disease-resistant bacterial community containing 10 high- and three low-abundance bacteria enriched in diseased roots. After the joint selection of plants and pathogens, the complex synthetic community was further simplified into a four-species community composed of three high-abundance bacteria ( Stenotrophomonas sp., Rhizobium sp., Ochrobactrum sp.) and one low-abundance bacterium ( Advenella sp.). Notably, a simple community containing these four strains and a thirteen-species community had similar effects on the control root rot disease. Furthermore, the simple community protected plants via a synergistic effect of highly abundant bacteria inhibiting fungal pathogen growth and less abundant bacteria activating plant-induced systemic resistance. Conclusions Our findings suggest that bacteria with low abundance play an important role in synthetic communities and that only a few bacterial taxa enriched in diseased roots are associated with disease resistance. Therefore, the construction and simplification of synthetic communities found in the present study could be a strategy employed by plants to adapt to environmental stress. -VujMZjCpFzTumqS8Rf9nH Video abstract

Astragalus mongholicus is a widely used Traditional Chinese Medicine. However, cultivated A. mongholicus is often threatened by water shortage at all growth stage, and the content of medicinal compounds of cultivated A. mongholicus is much lower than that of wild plants. To alleviate drought stress on A. mongholicus and improve the accumulation of medicinal components in roots of A. mongholicus , we combined different bacteria with plant growth promotion or abiotic stress resistance characteristics and evaluated the role of bacterial consortium in helping plants tolerate drought stress and improving medicinal component content in roots simultaneously. Through the determination of 429 bacterial strains, it was found that 97 isolates had phosphate solubilizing ability, 63 isolates could release potassium from potash feldspar, 123 isolates could produce IAA, 58 isolates could synthesize ACC deaminase, and 21 isolates could secret siderophore. Eight bacterial consortia were constructed with 25 bacterial isolates with more than three functions or strong growth promoting ability, and six out of eight bacterial consortia significantly improved the root dry weight. However, only consortium 6 could increase the root biomass, astragaloside IV and calycosin-7-glucoside content in roots simultaneously. Under drought challenge, the consortium 6 could still perform these functions. Compared with non-inoculated plants, the root dry weight of consortium inoculated-plants increased by 120.0% and 78.8% under mild and moderate drought stress, the total content of astragaloside IV increased by 183.83% and 164.97% under moderate and severe drought stress, calycosin-7-glucoside content increased by 86.60%, 148.56% and 111.45% under mild, moderate and severe drought stress, respectively. Meanwhile, consortium inoculation resulted in a decrease in MDA level, while soluble protein and proline content and SOD, POD and CAT activities increased. These findings provide novel insights about multiple bacterial combinations to improve drought stress responses and contribute to accumulate more medicinal compounds.

Global warming has a severe impact on the flowering time and yield of crops. Histone modifications have been well-documented for their roles in enabling plant plasticity in ambient temperature. However, the factor modulating histone modifications and their involvement in habitat adaptation have remained elusive. In this study, through genome-wide pattern analysis and quantitative-trait-locus (QTL) mapping, we reveal that BrJMJ18 is a candidate gene for a QTL regulating thermotolerance in thermotolerant B. rapa subsp. chinensis var. parachinensis (or Caixin, abbreviated to Par ). BrJMJ18 encodes an H3K36me2/3 Jumonji demethylase that remodels H3K36 methylation across the genome. We demonstrate that the BrJMJ18 allele from Par (BrJMJ18 Par ) influences flowering time and plant growth in a temperature-dependent manner via characterizing overexpression and CRISPR/Cas9 mutant plants. We further show that overexpression of BrJMJ18 Par can modulate the expression of BrFLC3 , one of the five BrFLC orthologs. Furthermore, ChIP-seq and transcriptome data reveal that BrJMJ18 Par can regulate chlorophyll biosynthesis under high temperatures. We also demonstrate that three amino acid mutations may account for function differences in BrJMJ18 between subspecies. Based on these findings, we propose a working model in which an H3K36me2/3 demethylase, while not affecting agronomic traits under normal conditions, can enhance resilience under heat stress in Brassica rapa . The study reveals that the BrJMJ18 gene, encoding an H3K36me2/3 Jumonji demethylase, is a candidate gene for a QTL regulating thermotolerance in a thermotolerant Brassica rapa subspecies, and its allele ( BrJMJ18 Par ) can modulate flowering time, plant growth, and chlorophyll biosynthesis in a temperature-dependent manner.

Religiosity and scientificity have long been intertwined in missionary anthropology. Since the 20th century, there has been a shift from religious missionary anthropology to scientific anthropology worldwide. Reviewing published materials and archives, this paper provides a case study of this transformation. It focuses on how the foreign missionary-founded West China Border Research Society transformed from a relatively closed and fixed local Christian academic research institution into a more open, international, and purely scientific research institution disciplined by Christian rationality. It sheds some new light into the Society’s roles and its transformation process. Contrary to the views of many scholars who assert that the Society “died” in 1937 and subsequently engaged in China’s state service and nation-building efforts, we contend that after 1937, the Society sought greater independence and a more scientific approach. Christianity dominated the Society in the early stages after its inception in 1922 in Chengdu, China, and its research results could not be objective or scientific. Although the Society later became more open and globalized, missionary anthropologists still mainly controlled it. After 1937, missionary anthropologists returned to religious rationality under the pressure of being connected to global academia. The Society eventually adopted “salvage anthropology” and tried to develop into a scientific research institution aimed at objective recording, while this somewhat rigid research approach also disciplined and suppressed the nationalist research orientation of Chinese colleagues and scholars. In response, Chinese researchers established other institutions and journals with stronger nationalism and undertook the “border construction work” that the Society could not accomplish.

GRAS proteins belong to a plant-specific transcription factor family and play roles in diverse physiological processes and environmental signals. In this study, we identified and characterized a GRAS transcription factor gene in , an ortholog of Arabidopsis . was primarily expressed in the roots and axillary meristems, and localized exclusively in the nucleus of protoplast cells. qRT-PCR analysis indicated that was upregulated by exogenous abscisic acid (ABA) and abiotic stress treatment [polyethylene glycol (PEG), NaCl, and H O ]. -overexpressing Arabidopsis plants exhibited pleiotropic characteristics, including morphological changes, delayed bolting and flowering time, reduced fertility and delayed senescence. Transgenic plants also displayed significantly enhanced drought resistance with decreased accumulation of ROS and increased antioxidant enzyme activity under drought treatment compared with the wild-type. Increased sensitivity to exogenous ABA was also observed in the transgenic plants. qRT-PCR analysis further showed that expression of several genes involved in stress responses and associated with leaf senescence were also modified. These findings suggest that encodes a stress-responsive GRASs transcription factor that positively regulates drought stress tolerance, suggesting a role in breeding programs aimed at improving drought tolerance in plants.

Cation-disordered rock salt (DRX) cathodes exhibit high specific capacity due to the simultaneous use of anionic and cationic redox reactions. However, DRX systems face severe challenges that limit their practical applications; a most important challenge is their poor rate performance. In this work, the structure and morphology of Li1.17Ti0.58Ni0.25O2 (LTNO) were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), etc. In combination with various electrochemical characterizations, we found that the sluggish kinetics of anionic redox within LTNO can be the key reason for the inferior rate performance. By sample relaxation at moderate temperature and X-ray absorption near edge structure (XANES), the ligand-to-metal charge transfer process is verified to occur between O and Ni and exhibits a prolonged characteristic time of 113.8 min. This time-consuming charge transfer process is verified to be the very fundamental origin of the slow kinetics of oxygen oxidation and reduction. This claim is further supported by the galvanostatic intermittent titration technique (GITT) at different temperatures. These findings provide essential guidance for understanding and further optimizing cathodes with anion redox reactions not only in the context of DRX cathodes but also conventional Li-rich cathodes.

Leaf curling is an essential prerequisite for the formation of leafy heads in Chinese cabbage. However, the part or tissue that determines leaf curvature remains largely unclear. In this study, we first introduced the auxin-responsive marker DR5::GUS into the Chinese cabbage genome and visualized its expression during the farming season. We demonstrated that auxin response is adaxially/abaxially distributed in leaf veins. Together with the fact that leaf veins occupy considerable proportions of the Chinese cabbage leaf, we propose that leaf veins play a crucial supporting role as a framework for heading. Then, by combining analyses of QTL mapping and a time-course transcriptome from heading Chinese cabbage and non-heading pak choi during the farming season, we identified the auxin-related gene BrPIN5 as a strong candidate for leafy head formation. PIN5 displays an adaxial/abaxial expression pattern in leaf veins, similar to that of DR5::GUS , revealing an involvement of BrPIN5 in leafy head development. The association of BrPIN5 function with heading was further confirmed by its haplo-specificity to heading individuals in both a natural population and two segregating populations. We thus conclude that the adaxial/abaxial patterning of auxin and auxin genes in leaf veins functions in the formation of the leafy head in Chinese cabbage.

Background The primary method utilized by orchard owners to combat Cydia pomonella is the application of various chemical insecticides. However, this has resulted in the development of resistance. The resistance mechanisms to insecticides from different chemical classes are diverse but interconnected. Therefore, it is crucial to comprehend the commonalities in these mechanisms to effectively develop strategies for managing resistance. Materials and methods To determine whether target-site insensitivity to LCT and AM plays a role in resistance, the sequences of voltage-gated sodium channel ( VGSC ) and glutamate-gated chloride channel ( GluCl ) containing the mutation domains were detected. To validate whether similar mechanisms were involved in the detoxification process of lambda-cyhalothrin (LCT) and abamectin (AM) at sublethal doses (specifically LD 10 and LD 30 ), cytochrome P450 monooxygenases (P450), glutathione S -transferases (GST), and carboxylesterases (CarE) activities were evaluated after insecticides exposure; synergistic experiments were conducted using piperonyl butoxide (PBO), diethyl maleate (DEM), and triphenyl phosphate (TPP) as inhibitors of P450, GST, and CarE respectively. RNA-sequencing (RNA-Seq) was performed to compare the expression levels of detoxification-related genes between susceptible (SS) and resistant strains. Results The best known target-site mutations caused by LCT and AM, including L1014F in VGSC and V263I, A309V, I321T, and G326E in GluCl were not occurred. We observed that PBO had a strong synergistic effect on LCT and AM, while DEM on LCT. The activities of detoxification enzymes increased after insecticide exposures, indicating that the detoxification of LCT was primarily carried out by P450 and CarE enzymes, while P450 and GST enzymes played a major role in the detoxification of AM. A total of 72 P450 genes and 75 CarE genes were identified in the C. pomonella transcriptome, with 43 of these genes (including 11 P450, 3 GST, 10 CarE, 11 ABC transporters, and 8 UDP-glycosyl transferases) being over-expressed in response to both insecticides Interestingly, ABC transporters were predominantly induced by AM treatment, while GST showed higher induction levels with LCT treatment. Furthermore, LCT-resistant strains of C. pomonella exhibited higher levels of induction of detoxification-related genes compared to susceptible strains. Conclusion The up-regulation of these detoxification genes is a common metabolic mechanism employed by C. pomonella to counteract the effects of insecticides, although the extent of gene expression change varies depending on the specific insecticide.

Carotenoid esterification plays indispensable roles in preventing degradation and maintaining the stability of carotenoids. Although the carotenoid biosynthetic pathway has been well characterized, the molecular mechanisms underlying carotenoid esterification, especially in floral organs, remain poorly understood. In this study, we identified a natural mutant flowering Chinese cabbage (Caixin, Brassica rapa L. subsp. chinensis var. parachinensis ) with visually distinguishable pale-yellow petals controlled by a single recessive gene. Transmission electron microscopy (TEM) demonstrated that the chromoplasts in the yellow petals were surrounded by more fully developed plastoglobules compared to the pale-yellow mutant. Carotenoid analyses further revealed that, compared to the pale-yellow petals, the yellow petals contained high levels of esterified carotenoids, including lutein caprate, violaxanthin dilaurate, violaxanthin-myristate-laurate, 5,6epoxy-luttein dilaurate, lutein dilaurate, and lutein laurate. Based on bulked segregation analysis and fine mapping, we subsequently identified the critical role of a phytyl ester synthase 2 protein ( PALE YELLOW PETAL , BrPYP ) in regulating carotenoid pigmentation in flowering Chinese cabbage petals. Compared to the yellow wild-type, a 1,148 bp deletion was identified in the promoter region of BrPYP in the pale-yellow mutant, resulting in down-regulated expression. Transgenic Arabidopsis plants harboring beta-glucuronidase (GUS) driven by yellow ( BrPYP Y ::GUS ) and pale-yellow type ( BrPYP PY ::GUS ) promoters were subsequently constructed, revealing stronger expression of BrPYP Y ::GUS both in the leaves and petals. Furthermore, virus-induced gene silencing of BrPYP significantly altered petal color from yellow to pale yellow. These findings demonstrate the molecular mechanism of carotenoid esterification, suggesting a role of phytyl ester synthase in carotenoid biosynthesis of flowering Chinese cabbage.

Brassica downy mildew, a severe disease caused by Hyaloperonospora brassicae, can cause enormous economic losses in Chinese cabbage (Brassica rapa L. ssp. pekinensis) production. Although some research has been reported recently concerning the underlying resistance to this disease, no studies have identified or characterized long noncoding RNAs involved in this defense response. In this study, using high-throughput RNA sequencing, we analyzed the disease-responding mRNAs and long noncoding RNAs in two resistant lines (T12–19 and 12–85) and one susceptible line (91–112). Clustering and Gene Ontology analysis of differentially expressed genes (DEGs) showed that more DEGs were involved in the defense response in the two resistant lines than in the susceptible line. Different expression patterns and proposed functions of differentially expressed long noncoding RNAs among T12–19, 12–85, and 91–112 indicated that each has a distinct disease response mechanism. There were significantly more cis- and trans-functional long noncoding RNAs in the resistant lines than in the susceptible line, and the genes regulated by these RNAs mostly participated in the disease defense response. Furthermore, we identified a candidate resistance-related long noncoding RNA, MSTRG.19915, which is a long noncoding natural antisense transcript of a MAPK gene, BrMAPK15. Via an agroinfiltration-mediated transient overexpression system and virus-induced gene silencing technology, BrMAPK15 was indicated to have a greater ability to defend against pathogens. MSTRG.19915-silenced seedlings showed enhanced resistance to downy mildew, probably because of the upregulated expression of BrMAPK15. This research identified and characterized long noncoding RNAs involved in resistance to downy mildew, laying a foundation for future in-depth studies of disease resistance mechanisms in Chinese cabbage.