Global warming is primarily characterized by asymmetric temperature increases, with greater temperature rises in winter/spring and at night compared to summer/autumn and the daytime.  We investigated the impact of winter night warming on the top expanded leaves of the spring wheat cultivar Yangmai 18 and the semi-winter wheat cultivar Yannong 19 during the 2020–2021 growing season.  Results showed that the night-time mean temperature in the treatment group was 1.27°C higher than the ambient temperature, and winter night warming increased the yields of both wheat cultivars, the activities of sucrose synthase and sucrose phosphate synthase after anthesis, and the biosynthesis of sucrose and soluble sugars.  Differentially expressed genes (DEGs) were identified using criteria of P-value<0.05 and fold change>2, and they were subjected to Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses.  Genes differentially expressed in wheat leaves treated with night warming were primarily associated with starch and sucrose metabolism, amino acid biosynthesis, carbon metabolism, plant hormone signal transduction, and amino sugar and nucleotide sugar metabolism.  Comparisons between the groups identified 14 DEGs related to temperature.  These results highlight the effects of winter night warming on wheat development from various perspectives.  Our results provide new insights into the molecular mechanisms of the response of wheat to winter night warming and the candidate genes involved in this process.

Global climate change is characterized by asymmetric warming, i.e., greater temperature increases in winter, spring, and nighttime than in summer, autumn, and daytime.  Field experiments were conducted using four wheat cultivars, namely ‘Yangmai 18’ (YM18), ‘Sumai 188’ (SM188), ‘Yannong 19’ (YN19), and ‘Annong 0711’ (AN0711), in the two growing seasons of 2019–2020 and 2020–2021, with passive night warming during different periods in the early growth stage.  The treatments were night warming during the tillering–jointing (NW_T–J), jointing–booting (NW_J–B), and booting–anthesis (NW_B–A) stages, with ambient temperature (NN) as the control.  The effects of night warming during different stages on wheat yield formation were investigated by determining the characteristics of dry matter accumulation and translocation, as well as sucrose and starch accumulation in wheat grains.  The wheat yields of all four cultivars were significantly higher in NW_T–J than in NN in the 2-year experiment.  The yield increases of semi-winter cultivars YN19 and AN0711 were greater than those of spring cultivars YM18 and SM188.  Treatment NW_T–J increased wheat yield mainly by increasing the 1,000-grain weight and the number of fertile spikelets, and it increased dry matter accumulation in various organs of wheat at the anthesis and maturity stages by increasing the growth rate at the vegetative growth stage.  The flag leaf and spike showed the largest increases in dry matter accumulation.  NW_T–J also increased the grain sucrose and starch contents in the early and middle grain-filling stages, promoting yield formation.  Overall, night warming between the tillering and jointing stages increased the pre-anthesis growth rate, and thus, wheat dry matter production, which contributed to an increase in wheat yield.

α-Linolenic acid (ALA, 18:3Δ9,12,15) is an essential fatty acid for humans since it is the precursor for the biosynthesis of omega-3 long-chain polyunsaturated fatty acids (LC-PUFA). Modern people generally suffer from deficiency of ALA because most staple food oils are low or lack ALA content. Biotechnological enrichment of ALA in staple oil crops is a promising strategy. Chia (Salvia hispanica) has the highest ALA content in its seed oil among known oil crops. In this study, the FAD2 and FAD3 genes from chia were engineered into a staple oil crop, oilseed rape (Brassica napus), via Agrobaterium tumefaciens-mediated transformation of their LP4-2A fusion gene construct driven by the seed-specific promoter PNapA. In seeds of T0, T1, and T2 lines, the average ALA contents were 20.86, 23.54, and 24.92%, respectively, which were 2.21, 2.68, and 3.03 folds of the non-transformed controls (9.42, 8.78, and 8.22%), respectively. The highest seed ALA levels of T0, T1, and T2 plants were 38.41, 35.98, and 39.19% respectively, which were 4.10–4.77 folds of the respective controls. FA-pathway enzyme genes (BnACCD, BnFATA, BnSAD, BnSCD, BnDGAT1, BnDGAT2, and BnDGAT3) and positive regulatory genes (BnWRI1, BnLEC1, BnL1L, BnLEC2, BnABI3, BnbZIP67, and BnMYB96) were all significantly up-regulated. In contrast, BnTT1, BnTT2, BnTT8, BnTT16, BnTTG1, and BnTTG2, encoding negative oil accumulation regulators but positive secondary metabolism regulators, were all significantly down-regulated. This means the foreign ShFAD2-ShFAD3 fusion gene, directly and indirectly, remodeled both positive and negative loci of the whole FA-related network in transgenic B. napus seeds.

Chinese cabbage is an economically important Brassica vegetable worldwide, and clubroot, which is caused by the soil-borne protist plant pathogen Plasmodiophora brassicae is regarded as a destructive disease to Brassica crops.  Previous studies on the gene transcripts related to Chinese cabbage resistance to clubroot mainly employed RNA-seq technology, although it cannot provide accurate transcript assembly and structural information.  In this study, PacBio RS II SMRT sequencing was used to generate full-length transcriptomes of mixed roots at 0, 2, 5, 8, 13, and 22 days after P. brassicae infection in the clubroot-resistant line DH40R.  Overall, 39 376 high-quality isoforms and 26 270 open reading frames (ORFs) were identified from the SMRT sequencing data.  Additionally, 426 annotated long noncoding RNAs (lncRNAs), 56 transcription factor (TF) families, 1 883 genes with poly(A) sites and 1 691 alternative splicing (AS) events were identified.  Furthermore, 1 201 of the genes had at least one AS event in DH40R.  A comparison with RNA-seq data revealed six differentially expressed AS genes (one for disease resistance and five for defensive response) that are potentially involved in P. brassicae resistance.  The results of this study provide valuable resources for basic research on clubroot resistance in Chinese cabbage.

In maize, two root epidermis-expressed ammonium transporters ZmAMT1;1a and ZmAMT1;3 play major roles in high-affinity ammonium uptake.  However, the transcriptional regulation of ZmAMT1s in roots for ensuring optimal ammonium acquisition remains largely unknown.  Here, using a split root system we showed that ZmAMT1;1a and ZmAMT1;3 transcript levels were induced by localized ammonium supply to nitrogen-deficient roots.  This enhanced expression of ZmAMT1s correlated with increases in ¹⁵NH₄⁺ influx rates and tissue glutamine concentrations in roots.  When ammonium was supplied together with methionine sulfoximine, an inhibitor of glutamine synthase, ammonium-induced expression of ZmAMT1s disappeared, suggesting that glutamine rather than ammonium itself regulated ZmAMT1s expression.  When glutamine was supplied to nitrogen-deficient roots, expression levels of ZmAMT1s were enhanced, and negative feedback regulation could subsequently occur by supply of glutamine at a high level.  Thus, our results indicated an ammonium-dependent regulation of ZmAMT1s at transcript levels, and a dual role of glutamine was suggested in the regulation of ammonium uptake in maize roots.

Somatic embryogenesis (SE) is one of the most important steps during regeneration of cotton, but the molecular mechanism of SE remains unclear.  SOMATIC EMBRYOGENSIS RECEPTOR KINASE (SERK) gene is known to function in SE.  A homolog GhSERK2 (accession number: JF430801) was cloned from Upland cotton and characterized for its functions in SE.  GhSERK2 expressed in different tissues and showed higher expression level in floral organs than vegetative ones with the highest levels in ovule and anther.  GhSERK2 expressed during SE with a high level at globular embryos stage.  Upon treatment with indole-3-butytic acid (IBA), the transcription level of GhSERK2 was induced and promoted SE subsequently.  A 2-day treatment of 2,4-dichlorophenoxyacetic acid (2,4-D) induced the expression of GhSERK2, but treatments of 2,4-D for longer periods sharply inhibited the GhSERK2 transcription level of embryogenic callus (EC).  The levels of hormones, including 3-indoleacetic acid (IAA), abscisic acid (ABA), and brassinosteroid (BR), were increased in the initial calli induced from the over-expression of GhSERK2 cotton.  Our results indicated that GhSERK2 expression was associated with induction of SE and closely related to hormone levels during tissue culture in Upland cotton, and the gene might play an important role in regeneration of cotton.

The germplasm resources for the S-type male sterility is rich in maize and it is resistant to Bipolaris maydis race T and CI, but the commercial application of S-type cytoplasmic male sterility (CMS-S) in maize hybrid industry is greatly compromised because of its common fertility instability. Currently, the existence of multiple minor effect loci in specific nuclear genetic backgrounds was considered as the molecular mechanism for this phenomenon. In the present study, we evaluated the fertility segregation of the different populations with the fertility instable material FIL-H in two environments of Beijing and Hainan, China. Our results indicated that the fertility instability of FIL-H was regulated by multiple genes, and the expression of these genes was sensitive to environmental factors. Using RNA sequencing (RNA-seq) technology, transcriptomes of the sterile plants and partially fertile plants resulted from the backcross of FIL-H×Jing 724 in Hainan were analyzed and 2 108 genes with different expression were identified, including 1 951 up-regulated and 157 down-regulated genes. The cluster analysis indicated that these differentially expressed genes (DEGs) might play roles in many biological processes, such as the energy production and conversion, carbohydrate metabolism and signal transduction. In addition, the pathway of the starch and sucrose metabolism was emphatically investigated to reveal the DEGs during the process of starch biosynthesis between sterile and partially fertile plants, which were related to the key catalytic enzymes, such as ADP-G pyrophosphorylase, starch synthase and starch branching enzyme. The up-regulation of these genes in the partially fertile plant may promote the starch accumulation in its pollen. Our data provide the important theoretical basis for the further exploration of the molecular mechanism for the fertility instability in CMS-S maize.

      Plant defense responses against penetration or colonization of pathogens are mediated by activation and repression of a large array of genes. Host endogenous small RNAs are essential in gene expression reprogramming process. We identified a new Arabidopsis microRNA (miRNA) ath-miR38-3P by high-throughput sequencing and further confirmed it by Northern blot assay. Interestingly, ath-miR38-3P was highly induced after infection of the pathogen Sclerotinia sclerotiorum. Further analysis based on the miRNA target database demonstrated that ath-miR38-3P might target to five putative genes: AT2G03140, AT5G59430, AT5G66320, AT1G36620 and AT3G03820. To confirm the target, we conducted the quantitative real-time PCR to observe the expression pattern of each candidate gene. The results showed that only AT3G03820 was down-regulated after inoculation of S. sclerotiorum. In addition, overexpression of ath-miR38-3P down-regulates AT3G03820, suggesting AT3G03820 might represent the target for ath-miR38-3P. Our results may provide the useful information for further studying the biological function of a novel ath-miR38-3P and its targets in Arabidopsis-Sclerotinia interaction.

The harpin protein Hpa1 produced by the rice bacterial blight pathogen promotes plant growth and induces plant resistance to pathogens and insect pests. The region of 10-42 residues (Hpa110-42) in the Hpa1 sequence is critical as the isolated Hpa110-42 fragment is 1.3-7.5-fold more effective than the full length in inducing plant growth and resistance. Here we report that transgenic expression of Hpa110-42 in wheat induces resistance to English grain aphid, a dominant species of wheat aphids. Hpa110-42-induced resistance is effective to inhibit the aphid behavior in plant preference at the initial colonization stage and repress aphid performances in the reproduction, nymph growth, and instar development on transgenic plants. The resistance characters are correlated with enhanced expression of defense-regulatory genes (EIN2, PP2-A, and GSL10) and consistent with induced expression of defense response genes (Hel, PDF1.2, PR-1b, and PR-2b). As a result, aphid infestations are alleviated in transgenic plants. The level of Hpa110-42-induced resistance in regard to repression of aphid infestations is equivalent to the effect of chemical control provided by an insecticide. These results suggested that the defensive role of Hpa110-42 can be integrated into breeding germplasm of the agriculturally significant crop with a great potential of the agricultural application.

Combined with remote sensing data and meteorological data, cold damage risk was assessed for planting area of double cropping rice (DCR) in Hunan Province, China. A new methodology of cold damage risk assessment was built that apply to grid and have clear hazard-affected body. Each station cold damage annual frequency and average annual intensity of cold damage was calculated by using 1951-2010 station daily mean temperature and simple cold damage identification index. On this basis, average annual cold damage risk index was obtained by their product. The spatial analysis models of cold damage risk index about double-season early rice (DSER) and double-season later rice (DSLR) were established respectively by the relation of average annual cold damage risk index and its geographic factors. Critical threshold of level of average annual cold damage risk index for DSER and DSLR were respectively divided by the correlative equation of cold damage annual frequency and average annual intensity of cold damage. 2001-2010 planting area of DCR, acquired by time series analysis of MOD09A1 8-d composite land surface reflectance product, was as target of assessment. The results show average annual intensity of cold damage is exponential function of cold damage annual frequency, average annual cold damage risk index is directly proportional to cold damage cumulant and cold damage annual frequency, and is inversely proportional to happen times of cold damage and the square of statistical time sequence length. Cold damage risk of DSER is higher than DSLR in Hunan Province. In the 10-yr stacking map, DCR planting in low risk area accounted for 11.92% of total extraction area, in moderate risk area accounted for 69.62%, in high risk area accounted for 18.46%. According to the cold damage risk assessment result, DCR production can be guided to reduce cold damage losses.

MicroRNAs (miRNAs) are endogenous small RNAs that play important regulatory roles in the growth and development processes of plants and animals. In this study, we examined the expression profiles of pollen miRNAs from a maize S type cytoplasmic male sterile line and its fertility restored line. In total, 100 known miRNAs belonging to 20 families and 81 novel miRNAs belonging to 44 families were identified. Two and seven known miRNAs had significant expression difference between the two lines at the level of P-value<0.01 and 0.011.5 fold expression difference were verified by stem-loop RT-qPCR. Gene Ontology analysis of miRNA target genes revealed that these genes mainly participated in the transcriptional regulation processes.

Plants respond to drought stress with different physical manners, such as morphology and color of leaves. Thus, plants can be considered as a sort of living-sensors for monitoring dynamic of soil water content or the stored water in plant body. Because of difficulty to identify the early wilting symptom of plants from the results in 2D (two-dimension) space, this paper presented a preliminary study with 3D (three-dimension)-based image, in which a laser scanner was used for achieving the morphological information of zucchini (Cucurbita pepo) leaves. Moreover, a leaf wilting index (DLWIF) was defined by fractal dimension. The experiment consisted of phase-1 for observing the temporal variation of DLWIF and phase-2 for the validation of this index. During the experiment, air temperature, luminous intensity, and volumetric soil water contents (VSWC) were simultaneously recorded over time. The results of both phases fitted the bisector (line: 1:1) with R2=0.903 and REMS=0.155. More significantly, the influence of VSWC with three levels (0.22, 0.30, and 0.36 cm3 cm-3) on the response of plant samples to drought stress was observed from separated traces of DLWIF. In brief, two conclusions have been made: (i) the laser scanner is an effective tool for the non-contact detection of morphological wilting of plants, and (ii) defined DLWIF can be a promising indicator for a category of plants like zucchini.

Since its discovery a decade ago, microRNA has been identified as one of the major regulatory gene families in eukaryotic cells. Many functions of microRNAs have been revealed both in flora and fauna in recent years, but the transcriptional regulation of microRNA genes is not well-understood. In the present study, a series of primers were designed in the 2 000 nt upstream regions of porcine miR-181 and miR-1 and then the sequences were cloned into pGL3-basic vector to test their transcriptional activity. Dual-luciferase reporter assays showed that, the activity of 5´-flanking sequence of miR-181 started on construct -51, decreasing with the length of the fragment up to -444. The upstream 590 bp confer maximal transcriptional activity and the basal promoter activity is located within the -82 to +16 bp region. For miR-1, the activity starts on construct -50, decreasing with the length of the fragment up to -1 254 in despite of a bit of fluctuation, and the basal promoter activity is located within the -50 to +47 bp region. Furthermore, some putative regulation elements of both miR-181 and miR-1 were located. In addition, tissue distribution revealed that miR-181 is expressed at a relatively low level.

Natural rubber is an indispensable material of strategic importance that has critical applications in industry and the military. However, the development of the natural rubber industry is impeded by the red root rot disease of rubber trees caused by Ganoderma pseudoferreum, which is one of the most devastating diseases in the rubber tree growing regions in China. To combat this disease, we screened the antifungal activity of 223 candidate bacterial strains against G. pseudoferreum, and found that Bacillus velezensis strain SF305 exhibited significant antifungal activity against G. pseudoferreum. B. velezensis SF305 had a nearly 70% efficacy against the red root rot disease of rubber trees with the therapeutic treatment (Tre), while it exhibited over 90% protection effectiveness with the preventive treatment (Pre). The underlying biocontrol mechanism revealed that B. velezensis SF305 could reduce the disease severity of red root rot by degrading the mycelia of G. pseudoferreum. An antiSMASH analysis revealed that B. velezensis SF305 contains 15 gene clusters related to secondary metabolite synthesis, 13 of which are conserved in species of B. velezensis, but surprisingly, B. velezensis SF305 possesses 2 unique secondary metabolite gene clusters. One is predicted to synthesize locillomycin, and the other is a novel nonribosomal peptides synthetase (NRPS) gene cluster. Genomic analysis showed that B. velezensis SF305 harbors genes involved in motility, chemotaxis, biofilm formation, stress resistance, volatile organic compounds (VOCs) and synthesis of the auxin indole-3-acetic acid (IAA), suggesting its plant growth-promoting rhizobacteria (PGPR) properties. B. velezensis SF305 can promote plant growth and efficiently antagonize some important phytopathogenic fungi and bacteria. This study indicates that B. velezensis SF305 is a versatile plant probiotic bacterium. To the best of our knowledge, this is the first time a B. velezensis strain has been reported as a promising biocontrol agent against the red root rot disease of rubber trees. 

Stripe rust caused by Puccinia striiformis f. sp. tritici (Pst) is a serious disease affecting wheat production in China.  Wheat cultivar Aikang 58 (AK58) has exhibited effective resistance to stripe rust since its release in 2005.  But the genetic basis of its stripe rust resistance remains unknown. Two genetic populations from the crosses of Avocet S/AK58 (128 recombinant inbred lines) and Kenong 9204/AK58 (1,042 F_2:3 families) were used to dissect the genetic basis of stripe rust resistance in AK58, respectively. In addition, Panel 1 consisting of 688 wheat accessions were used for genome-wide association study (GWAS) and sweep selection analysis to validate the presence of the resistance haplotype of the target region and Panel 2 consisting of 388 Chinese cultivars and breeding lines was genotyped using molecular markers to evaluate the prevalence and distribution of the resistant loci in AK58. The genetic populations were evaluated for stripe rust responses at Yangling and Guiyang over five cropping seasons (2017-2022) and genotyped using GBW16 K SNP array and KASP markers. Using quantitative trait loci (QTLs) analysis, seven QTL were detected on chromosome arms 1BL, 2BS, 2BL, 5BL and 7BL (three QTLs).  Among them, QYrak.nwafu-2BL identified as Yr5b conferred all-stage resistance to Pst race V32L; three QTL within the 7BL chromosome arm region 715.77-733.25 Mb based on Chinese Spring RefSeq v.2.1, were designated YrAK58.1, YrAK58.2 and YrAK58.3, respectively.  YrAK58.1 confirmed as Yr6, and YrAK58.2 conferred all-stage resistance to multiple Pst races and were also effective in field environments. YrAK58.3 contributed stable resistance in all field environments. The remaining QTL were environment-dependent with minor effect. GWAS and sweep selection analyses revealed specific genomic regions with artificial selection signals for the three QTL on chromosome arm 7BL in different breeding groups.  A haplotype combination of high-throughput molecular markers tightly flanking Yr6, YrAK58.2 and YrAK58.3 detected all three genes in 3.6% of entries in Panel 2. The same marker set can be used to further exploit the resistance gene combination in breeding programs.