Mikania micrantha is a fast-growing global invasive weed species that causes severe damage to natural ecosystems and very large economic losses of forest and crop production.  It has advantages in photosynthesis, including a similar net photosynthetic rate as C₄ plants and a higher carbon fixation capacity.  We used a combination of genomics and transcriptomics approaches to study the evolutionary mechanisms and circadian expression patterns of M. micrantha.  In M. micrantha, 16 positive selection genes focused on photoreaction and utilization of photoassimilates.  In different tissues, 98.1% of the genes associated with photoresponse had high expression in stems, and more than half of the genes of the C₄ cycle had higher expression in stems than in leaves.  In stomatal opening and closing, 2 genes of carbonic anhydrase (CAs) had higher expression at 18:00 than at 8:00, and the slow anion channel 1 (SLAC1) and high-leaf-temperature 1 kinase (HT1) genes were expressed at low levels at 18:00.  In addition, genes associated with photosynthesis had higher expression levels at 7:00 and 17:00.  We hypothesized that M. micrantha may undergo photosynthesis in the stem and flower organs and that some stomata of the leaves were opening at night by CO₂ signals.  In addition, its evolution may attenuate photoinhibition at high light intensities, and enhance more efficient of photosynthesis during low light intensity.  And the tissue-specific photosynthetic types and different diurnal pattern of photosynthetic-related genes may contribute to its rapid colonization of new habitats of M. micrantha.

Understanding the composition and contents of carotenoids in various soybean seed accessions is important for their nutritional assessment.  This study investigated the variability in the concentrations of carotenoids and chlorophylls and revealed their associations with other nutritional quality traits in a genetically diverse set of Chinese soybean accessions comprised of cultivars and landraces.  Genotype, planting year, accession type, seed cotyledon color, and ecoregion of origin significantly influenced the accumulation of carotenoids and chlorophylls.  The mean total carotenoid content was in the range of 8.15–14.72 µg g^–1 across the ecoregions.  The total carotenoid content was 1.2-fold higher in the landraces than in the cultivars.  Soybeans with green cotyledons had higher contents of carotenoids and chlorophylls than those with yellow cotyledons.  Remarkably, lutein was the most abundant carotenoid in all the germplasms, ranging from 1.35–37.44 µg g^–1.  Carotenoids and chlorophylls showed significant correlations with other quality traits, which will help to set breeding strategies for enhancing soybean carotenoids without affecting the other components.  Collectively, our results demonstrate that carotenoids are adequately accumulated in soybean seeds, however, they are strongly influenced by genetic factors, accession type, and germplasm origin.  We identified novel germplasms with the highest total carotenoid contents across the various ecoregions of China that could serve as the genetic materials for soybean carotenoid breeding programs, and thereby as the raw materials for food sectors, pharmaceuticals, and the cosmetic industry.

Anthocyanin is an important pigment that affects plant color and nutritional quality.  MYBs play an important role in plant anthocyanin synthesis and accumulation.  However, the regulatory function of MYB transcription factors in anthocyanin synthesis in flax flowers is still unclear.  In this study, 402 MYB transcription factors were identified in the flax genome.  These MYB members are unevenly distributed on 15 chromosomes.  The R2R3-LuMYB members were divided into 32 phylogenetic subfamilies.  qRT-PCR analysis showed that seven R2R3-LuMYB genes in the adjacent subfamily of the evolutionary tree had similar expression patterns, among which LuMYB216 was highly expressed in the petals of different colors.  Moreover, gene editing of LuMYB216 in flax showed that the petal color, anther color and seed coat color of mutant plants were significantly lighter than those of wild-type plants, and the anthocyanin content of lumyb216 mutant plants was significantly reduced.  Correlation analysis indicated that LuMYB216 was significantly positively correlated with the upstream regulator bHLH30.  This study systematically analyzed the MYB gene family in flax, laying a foundation for studying the regulation of LuMYB216 in flax flower anthocyanin synthesis.

Increasing wheat yield is a long-term goal for wheat breeders around the world.  Exploiting elite genetic resources and dissecting the genetic basis of important agronomic traits in wheat are the necessary methods for high-yield wheat breeding.  This study evaluated nine crucial agronomic traits found in a natural population of 156 wheat varieties and 77 landraces from Sichuan, China in seven environments over two years.  The results of this investigation of agronomic traits showed that the landraces had more tillers and higher kernel numbers per spike (KNS), while the breeding varieties had higher thousand-kernel weight (TKW) and kernel weight per spike (KWS).  The generalized heritability (H²) values of the nine agronomic traits varied from 0.74 to 0.95.  Structure analysis suggested that the natural population could be divided into three groups using 43 198 single nucleotide polymorphism (SNP) markers from the wheat 55K SNP chip.  A total of 67 quantitative trait loci (QTLs) were identified by the genome-wide association study (GWAS) analysis based on the Q+K method of a mixed linear model.  Three important QTLs were analyzed in this study.  Four haplotypes of QFTN.sicau-7BL.1 for fertile tillers number (FTN), three haplotypes of QKNS.sicau-1AL.2 for KNS, and four haplotypes of QTKW.sicau-3BS.1 for TKW were detected.  FTN-Hap2, KNS-Hap1, and TKW-Hap2 were excellent haplotypes for each QTL based on the yield performance of 42 varieties in regional trials from 2002 to 2013.  The varieties with all three haplotypes showed the highest yield compared to those with either two haplotypes or one haplotype.  In addition, the KASP-AX-108866053 marker of QTL QKNS.sicau-1AL.2 was successfully distinguished between three haplotypes (or alleles) in 63 varieties based on the number of kernels per spike in regional trials between 2018 and 2021.  These genetic loci and reliable makers can be applied in marker-assisted selection or map-based gene cloning for the genetic improvement of wheat yield. 

Excessive use of nitrogen fertilizer in China and its adverse effects on agricultural production have been a national and global concern. In addition to massive public initiatives to promote sustainable farm practices, grass-rooted innovations are emerging in the niche, many of which take the forms of information and communication technologies (ICT) and digital services. This study examines the effects of ICT-based extension services provided by an entrepreneurial startup on adopting sustainable farming practices. We found no significant reduction in N-fertilizer use for wheat production. But the ICT-based services promoted farmers to adapt N-fertilizer use towards site-specific management. The business model of the entrepreneurial venture faces great challenges in becoming participatory and financially sustainable.

Now, lodging is a major constraint factor contributing to yield loss of maize (Zea mays L.) under high planting density. Chemical regulation and nitrogen fertilizer could effectively coordinate the relationship between stem lodging and maize yield, which significantly reduce lodging and improve the grain yield. The purpose of this study was to explore the effects of chemical regulation and different nitrogen application rates on lodging characteristics, grain filling and yield of maize under high density. For this, we established a field study during 2017 and 2018 growing seasons, with three nitrogen levels of N100 (100 kg ha^–1), N200 (200 kg ha^–1) and N300 (300 kg ha^–1) at high planting density (90 000 plants ha^–1), and applied plant growth regulator (Yuhuangjin, the mixture of 3% DTA-6 and 27% ethephon) at the 7th leaf. The results showed that chemical control increased the activities of phenylalanine ammonia-lyase (PAL), tyrosine ammonia-lyase (TAL), 4-coumarate:CoA ligase (4CL), and cinnamyl alcohol dehydrogenase (CAD), and increased the lignin, cellulose and hemicellulose contents at the bottom of the 3rd internode, which significantly reduced the lodging percentage. The lignin-related enzyme activities, lignin, cellulose and hemicellulose contents decreased with the increase of nitrogen fertilizer, which significantly increased the lodging percentage. The 200 kg ha^–1 nitrogen application and chemical control increased the number, diameter, angle, volume, and dry weight of brace roots. The 200 kg ha^–1 nitrogen application and chemical control significantly increased the activities of ADP-glucose pyrophosphorylase (AGPase), soluble starch synthase (SSS) and starch branching enzyme (SBE), which promoted the starch accumulation in grains. Additional, improved the maximum grain filling rate (V_max) and mean grain filling rate (V_m), which promoted the grain filling process, significantly increased grain weight and grain number per ear, thus increased the final yield.

Chinese vegetable production cooperatives supply their members, mostly smallholder farmers, with a rotation schedule for the year.  Since vegetable prices are not stable throughout the year, designing a rotation schedule that maximizes expected profits, distributes farmers’ profits more equitably, maintains the diversity of produce in the market, and reduces the risk of pests and diseases, requires adaptive, price-contingent rotation schedules (here, called “self-adaptive adjustment”).  This study uses an agent-based simulation (ABS) to design self-adaptive rotation schedules that deliver these aims.  The self-adaptive adjustment strategy was more profitable for farmers when faced with price volatility, and more equitable as well.  This work provides a decision-support tool for managers of Chinese vegetable production cooperatives to provide farmers with more profitable and equitable rotation schedules.   

Melatonin is a naturally occurring compound in plants.  Here, we tested the effect of exogenous melatonin on rapeseed (Brassica napus L.) grown under salt stress.  Application of 30 μmol L^–1 melatonin alleviated salt-induced growth inhibition, and the shoot fresh weight, the shoot dry weight, the root fresh weight, and the root dry weight of seedlings treated with exogenous melatonin increased by 128.2, 142.9, 122.2, and 124.2%, respectively, compared to those under salt stress.  In addition, several physiological parameters were evaluated.  The activities of antioxidant enzymes including peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) were enhanced by 16.5, 19.3, and 14.2% compared to their activities in plants without exogenous melatonin application under salt stress, while the H₂O₂ content was decreased by 11.2% by exogenous melatonin.  Furthermore, melatonin treatment promoted solute accumulation by increasing the contents of proline (26.8%), soluble sugars (15.1%) and proteins (58.8%).  The results also suggested that higher concentrations (>50 μmol L^–1) of melatonin could attenuate or even prevent the beneficial effects on seedling development.  In conclusion, application of a low concentration of exogenous melatonin to rapeseed plants under salt stress can improve the H₂O₂-scavenging capacity by enhancing the activities of antioxidant enzymes such as POD, CAT and APX, and can also alleviate osmotic stress by promoting the accumulation of osmoregulatory substances such as soluble proteins, proline, and water soluble glucan.  Ultimately, exogenous melatonin facilitates root development and improves the biomass of rapeseed seedlings grown under salt stress, thereby effectively alleviating the damage of salt stress in rapeseed seedlings.

   Loquat (Eriobotrya japonica Lindl.) can be divided into yellow- and white-fleshed cultivars by flesh color. However, a Dongting loquat mutant, which involved bud sport and growing white-fleshed fruit in the central region of the trunk (as wild loquat bears yellow-fleshed fruits naturally), was discovered in the preliminary study. The study cloned the coding sequence (CDS) of NAD⁺-dependent sorbitol dehydrogenase (NAD⁺-SDH ) gene from the selected materials of mutant loquat, wild loquat and other nine loquat cultivars/accessions, and found that the CDS of NAD⁺-SDH gene from the mutant loquat, other than the rest two types of materials, had three single nucleotide polymorphisms (SNPs) loci; in addition, the amino acid encoded at variation loci changed accordingly. NAD⁺-SDH plays an active role in converting sorbitol into fructose in loquat cultivars. For the mutant white-fleshed loquat, the activity of NAD⁺-SDH rises first and then drops, the sorbitol content decreases steadily, and its fructose content is higher than that in wild loquat from coloration to maturation stage. As demonstrated by the real-time fluorescence quantification PCR analysis, the expression level of NAD⁺-SDH gene at maturation stage is about 5-fold lower than wild type. It may be assumed that, the three SNPs loci might lead to excessive conversion of sorbitol into fructose under the catalytic action of NAD⁺-SDH of white-fleshed mutant loquat at maturation stage, resulting in the increase of fructose content and reduced expression abundance of mRNA after transcription. Besides, NAD⁺-SDH gene may be related to flesh color and carbohydrate variation of white-fleshed mutant loquat.

Ten populations of Radopholus similis from different ornamental hosts were tested for their parasitism and pathogenicity to water spinach (Ipomoea aquatic), malabar spinach (Basella rubra), and squash (Cucurbita moschata) in pots. The results showed all three plants were new hosts of R. similis. Growth parameters of plants inoculated with nematodes were significantly lower than those of healthy control plants. All R. similis populations were pathogenic to the three plants, but pathogenicity differed among populations from different hosts. The same R. similis populations also showed different pathogenic effects in the three different plants. RadN5 population from Anthurium andraeanum had the highest pathogenicity to the three studied plants. RadN1 from A. andraeanum had the lowest pathogenicity to squash and RadN7 from Chrysalidocarpus lutesens had the lowest pathogenicity to water spinach and malabar spinach. R. similis is usually associated with root tissues, but here we report that it could be found to move and feed in the stem bases of all three studied plants. Sequence and phylogenetic analyses of DNA markers of the 18S rRNA, 28S rRNA, ITS rRNA, and mitochondrial DNA gene sequences of ten R. similis populations revealed significant genetic diversity. RadN5 and RadN6 populations from anthurium showed a close genetic relationship and could be distinguished from other populations by PCR-RFLP. At the same time, RadN5 and RadN6 populations were the most pathogenic to three studied plants. These results confirm the existence of large biological variability and molecular diversity among R. similis populations from the same or different hosts, and these characteristics are related to pathogenic variability.

Conogethes punctiferalis (Guenée) (Lepidoptera: Crambidae) was originally considered as one species with fruit-feeding type (FFT) and pinaceae-feeding type (PFT), but it has subsequently been divided into two different species of Conogethes punctiferalis and Conogethes pinicolalis. The relationship between the two species was investigated by phylogenetic reconstruction using maximum-likelihood (ML) parameter estimations. The phylogenetic tree and network were constructed based upon sequence data from concatenation of three genes of mitochondrial cytochrome c oxidase subunits I, II and cytochrome b which were derived from 118 samples of C. punctiferalis and 24 samples of C. pinicolalis. The phylogenetic tree and network showed that conspecific sequences were clustering together despite intraspecific variability. Here we report the results of a combined analysis of mitochondrial DNA sequences from three genes and morphological data representing powerful evidence that C. pinicolalis and C. punctiferalis are significantly different.

Plants reshape their transcriptomes, proteomes and metabolomes in response to insect damage. In this study, we used suppression subtractive hybridization to investigate the transcriptomes of two cotton varieties (CCRI41 and CCRI23) under Apolygus lucorum damage. From the CCRI23 libraries we obtained 92 transcripts and from the CCRI41 libraries we obtained 96 transcripts. 26 and 63 of the transcripts from CCRI23 and CCRI41, respectively, had known functions. Using reverse transcription PCR, we detected expression profile of genes with known functions. Ultimately, we identified eight significantly regulated genes, including one downregulated and four upregulated genes from the CCRI41 libraries, and one downregulated and two upregulated genes from the CCRI23 libraries. Only the gene encoding the polyphenol oxidase (PPO) is involved in plant defense against insect herbivores, and the others are related to improving tolerance to insect damage. Quantitative real-time PCR was used to study changes in expression levels during A. lucorum damage in CCRI23 and CCRI41. Significantly regulated genes from CCRI23 showed a response in CCRI23 but not response in CCRI41. Similarly, significantly regulated genes from CCRI41 showed a response in CCRI41 but not response in CCRI23. The results showed that, among transcriptomes of cotton varieties, there are different responses to A. lucorum damage.

Alfalfa (Medicago sativa L.) is an important forage crop in the world and it is of great significance for the improvement of its salt tolerance. To improve salt tolerance in alfalfa, a rice ascorbate peroxidase gene (OsAPX2) was introduced into alfalfa using Agrobacterium tumefaciens-mediated transformation with marker gene bar. The different T-DNA insertions in T1 transgenic alfalfa were identified by Southern hybridization. Three independent T2 transgenic lines were selected for stress analysis and the results showed that all of them were salt tolerant compared with wild-type plants. The transgenic plants had low levels of H2O2, malondialdehyde and relative electrical conductivity under salt and drought stresses. Moreover, the contents of chlorophyll and proline, and APX activity were high in transgenic plants under salt and drought stresses. Taken together, the overexpression of OsAPX2 enhances salt tolerance in alfalfa through scavenging reactive oxygen species.

The importance of microRNA (miRNA) at the post-transcriptional regulation level has recently been recognized in both animals and plants. In recent years, many studies focused on miRNA target identification and functional analysis. However, little is known about the transcription and regulation of miRNAs themselves. In this study, the transcription start sites (TSSs) for 11 miRNA primary transcripts of soybean from 11 miRNA loci (of 50 loci tested) were cloned by a 5´ rapid amplification of cDNA ends (5´ RACE) procedure using total RNA from 30-d-old seedlings. The features consistent with a RNA polymerase II mechanism of transcription were found among these miRNA loci. A position weight matrix algorithm was used to identify conserved motifs in miRNA core promoter regions. A canonical TATA box motif was identified upstream of the major start site at 8 (76%) of the mapped miRNA loci. Several cis-acting elements were predicted in the 2 kb 5´ to the TSSs. Potential spatial and temporal expression patterns of the miRNAs were found. The target genes for these miRNAs were also predicted and further elucidated for the potential function of the miRNAs. This research provides a molecular basis to explore regulatory mechanisms of miRNA expression, and a way to understand miRNAmediated regulatory pathways and networks in soybean.

Drought is one of the major abiotic stresses that limit maize productivity. Apart from the principal transcriptional regulation, post-transcriptional regulation mediated by microRNAs appears to be the prevalent response of plants to abiotic stress. In this study, the differential expression of microRNAs in the previously evaluated drought-tolerant inbred lines R09 under drought stress was detected by microarray hybridization. The target genes of the differentially-expressed microRNAs were predicted by bioinformatics software WMD3 for plant target gene prediction. The possible regulation of the differentially-expressed microRNAs as well as their target genes in maize response to drought stress was analysed according to Gene Ontology. Sixty-eight microRNAs in 29 microRNA families were detected to be differentially expressed in the seedling of the drought-tolerant inbred line R09, accounting for 5.97% of the total number of the probes. The expression profiles were different between the two time points of the drought stress. The functions of the genes targeted by the differentially-expressed microRNAs involve multiple physiological and biochemical pathways of response to abiotic stress, such as transcription regulation, metabolism, signal transduction, hormone stimulation, and transmembrane transport. Under drought stress, the differential expression of microRNAs regulates the expression of their target genes, resulting in multiple responses of physiological and biochemical pathways relative to drought tolerance of maize. miR156, miR159 and miR319 families may play more important roles. The different members of the same family may play similar regulation effects in most cases.

The virulent strain B6 of Curvularia lunata was screened out from 65 fungus strains isolated from the diseased leaves of barnyardgrass (Echinochloa crus-galli). Greenhouse and field studies were conducted to evaluate the feasibility of the strain being exploited as a mycoherbicide for barnyardgrass control in paddy fields. The results of pathogenicity experiments showed that this strain was highly pathogenic to barnyardgrass at the 1- to 2.5-leaf stages. The fresh weight reduction increased with the increase of inoculated conidial concentrations and the prolongation of dew duration. Strain B6 provided excellent barnyardgrass control when it was applied at the concentration of 1×104-1×106 conidia mL-1 in paddy fields with water layer. This strain was very safe to rice and the most plant species except wheat, barley and corn. Findings of this study indicated that this strain could be a potential mycoherbicide for barnyardgrass control in paddy fields in the future.

Morphology and morphometry of six biotypes (B, Q, Cv, ZHJ-1, ZHJ-2 and ZHJ-3) of Bemisia tabaci (Gennadius) from China on cotton plants were studied by using microscopes. Nymphal body sizes and characters were measured and observed, especially on the 4th instar (pupal case), including the vasiform orifice, operculum, lingula, length and thickness of anterior and posterior wax margins, width of thoracic tracheal combs. Adult characters of both sexes were investigated including the body size, compound eyes, antennal segments, vasiform orifice, hind tarsi and genitals. The results indicated that differences of some morphological characters or morphometrics were significant among the six biotypes of B. tabaci in China: (1) Pupal sizes of the exotic biotypes (B and Q) were significantly larger than the indigenous biotypes with the following order as B>Q>ZHJ-1>Cv>ZHJ-3>ZHJ-2; (2) for both male and female adults, sizes of all characters investigated in the invading biotypes (B and Q), especially B, were much larger than those of the indigenous ones.

Wolbachia are maternally inherited endosymbiotic bacteria infecting a wide range of arthropods and filarial nematodes. They can induce various reproduction alterations in their hosts, including thelytokous parthenogenesis, cytoplasmic incompatibility (CI), feminization of genetic males and male killing. Here we investigated diversity and prevalence patterns of Wolbachia infection in 43 geographical populations of the Asian corn borer, Ostrinia furnacalis, in China and one population in North Korea. Based on Wolbachia surface protein gene (wsp) sequences, nine strains of Wolbachia (wFur1-wFur9), belonging to supergroups A and B, were identified in populations of O. furnacalis with an average infection rate of 10.5%. Superinfection commonly appeared in individuals of O. furnacalis and coinfection patterns were very complex. There was no specific pattern for the prevalence and distribution of the nine Wolbachia strains suggesting an intricate evolutionary history of Wolbachia infection in this species. The genetic similarity of the wFur1-wFur9 strains with those detected in two parasitoids of O. furnacalis, Macrocentrus cingulum and Lydella grisescens, strongly suggests host-parasitoid horizontal transmission.

14-3-3 proteins belong to a family of phosphoserine/threonine-binding modules and participate in a wide array of signal transduction and regulatory events. Our previous study demonstrated that Ta14-3-3 was significantly down-regulated in leaf and root tissues of hybrid wheat at the tillering stage. In this paper, three homoeologous Ta14-3-3 genes were cloned from common wheat (Triticum aestivum L., 2n=6x=42, AABBDD) and mapped on chromosomes 2A, 2B, and 2D, respectively. Transgenic Arabidopsis plants ectopically overexpressing Ta14-3-3 displayed shorter primary roots, delayed flowering and retarded growth rates, indicating that Ta14-3-3 acted as a growth inhibitor in Arabidopsis. In wheat, Ta14-3-3 was down-regulated in roots and leaves of hybrids as compared to their parental lines. We proposed that Ta14-3-3 proteins might regulate growth vigor in hybrid wheat.

Jojoba (Simmondsia chinensis) is mainly distributed in desert, and the molecular mechanisms of jojoba in response to abiotic stress still remain elusive. In this paper, we cloned and characterized a SOD gene from jojoba named as ScMnSOD, and introduced into Arabidopsis to investigate its functions of responding to drought stress. The transgenic Arabidopsis showed an improvement in drought tolerance. Moreover, under a water deficit condition, the accumulation of reactive oxygen species (ROS) was remarkably decreased in the transgenic lines compared to the WT. Furthermore, the ScMnSOD promoter was cloned to the 5´-upstream of GUS coding region in a binary vector, and introduced into Arabidopsis. And results showed that ScMnSOD expression can be induced by drought, salt, ABA, and low temperature. In conclusion, ScMnSOD plays an important role in drought tolerance which is, at least partially, attributed to its role in ROS detoxification.

2,4-Dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one (DIMBOA), the dominant benzoxazinoid hydroxamic acid in maize (Zea Mays L.), serves as important factors of resistance against insects and microbial diseases, allelochemicals used in competition with other plants. In this paper, a novel and simple method for the isolation and purification of DIMBOA from maize seedlings was developed. Frozen shoots from 7-d-old maize seedlings (1 000×g) were firstly defrosted and then were directly homogenized and extracted with ethyl acetate. The macerate was allowed to stand at room temperature (25±2)°C for 1 h to allow enzymatic release of DIMBOA from DIMBOA-glucoside. Then the ethyl acetate phase was filtered, dried and evaporated to dryness. The resulting light-tan, semicrystalline residue was stored at -20°C for 24 h. Upon recrystallization from acetone-hexane, a relative higher yield (0.58 g) of pure DIMBOA crystals was obtained compared with the yield afforded by Woodward methodology (0.26 g).

This paper introduces efforts and achievements of Agriculture Ontology Service Research Group of Agricultural Information Institute of Chinese Academy of Agriculture Sciences in last 10 years. It summarizes the research on ontology construction methodology, ontology management system, ontology application and etc.