Developing and excavating new agrochemicals with highly active and safe is an important tactic for protecting crop health and food safety.  In this paper, to discover the new bactericide candidates, we designed, prepared a new type of 1,2,3,4-tetrahydro-β-carboline (THC) derivatives and evaluated the in vitro and in vivo bioactivities against the Xanthomonas oryzae pv. oryzae (Xoo), Xanthomonas axonopodis pv. citri (Xac), and Pseudomonas syringae pv. actinidiae (Psa).  The in vitro bioassay results exhibited that most title molecules possessed good activity toward the three plant pathogenic bacteria, the compound A₁₇ showed the most active against Xoo and Xac with EC₅₀ values of 7.27 and 4.89 mg mL^–1 respectively, and compound A₈ exhibited the best inhibitory activity against Psa with EC₅₀ value of 4.87 mg mL^–1.  Pot experiments showed that compound A₁₇ exhibited excellent in vivo antibacterial activities to manage rice bacterial leaf blight and citrus bacterial canker, with protective efficiencies of 52.67 and 79.79% at 200 mg mL^–1, respectively.  Meanwhile, compound A₈ showed good control efficiency (84.31%) against kiwifruit bacterial canker at 200 mg mL^–1.  Antibacterial mechanism suggested that these compounds could interfere with the balance of the redox system, damage the cell membrane, and induce the apoptosis of Xoo cells.  Taken together, our study revealed that tetrahydro-β-carboline derivatives could be a promising candidate model for novel broad-spectrum bactericides.

High-molecular-weight glutenin subunits (HMW-GSs) are the most critical grain storage proteins that determine the unique processing qualities of wheat. Although it is a part of the superior HMW-GS pair (Dx5+Dy10), the contribution of the Dy10 subunit to wheat processing quality remains unclear. In this study, we elucidated the effect of Dy10 on wheat processing quality by generating and analyzing a deletion mutant (with the Dy10-null allele), and by elucidating the changes to wheat flour following the incorporation of purified Dy10. The Dy10-null allele was transcribed normally, but the Dy10 subunit was lacking. These findings implied that the Dy10-null allele reduced the glutenin:gliadin ratio and negatively affected dough strength (i.e., Zeleny sedimentation value, gluten index, and dough development and stability times) and the bread-making quality; however, it positively affected the biscuit-making quality. The incorporation of various amounts of purified Dy10 into wheat flour had a detrimental effect on biscuit-making quality. The results of this study demonstrate that the Dy10 subunit is essential for maintaining wheat dough strength. Furthermore, the Dy10-null allele may be exploited by soft wheat breeding programs.

Soil salinity affects the expression of serine/arginine-rich (SR) genes and isoforms by alternative splicing, which in turn regulates the adaptation of plants to stress.  We previously identified the cassava spliceosomal component 35 like (SCL) and SR subfamilies, belonging to the SR protein family, which are extensively involved in responses to abiotic stresses.  However, the post-transcriptional regulatory mechanism of cassava arginine/serine-rich (RS) subfamily in response to salt stress remains to be explored.  In the current study, we identified 37 genes of the RS subfamily from 11 plant species and systematically investigated the transcript levels of the RS40 and RS31 genes under diverse abiotic stress conditions.  Subsequently, an analysis of the conserved protein domains revealed that plant RS subfamily genes were likely to preserve their conserved molecular functions and played critical functional roles in responses to abiotic stresses.  Importantly, we found that overexpression of MeRS40 in Arabidopsis enhanced salt tolerance by maintaining reactive oxygen species homeostasis and up-regulating the salt-responsive genes.  However, overexpression of MeRS40 gene in cassava reduced salt tolerance due to the depression of its endogenous gene expression by negative autoregulation of its own pre-mRNA.  Moreover, the MeRS40 protein interacted with MeU1-70Ks (MeU1-70Ka and MeU1-70Kb) in vivo and in vitro, respectively.  Therefore, our findings highlight the critical role of cassava SR proteins in responses to salt stress in plants. 

Potato is one of the staple food crops in North China.  However, potato production in this region is threatened by the low amount and high spatial-temporal variation of precipitation.  Increasing yield and water use efficiency (WUE) of potato by various water management practices under water resource limitation is of great importance for ensuring food security in China.  However, the contributions of different water management practices to yield and WUE of potato have been rarely investigated across North China’s potato planting region.  Based on meta-analysis of field experiments from the literature and model simulation, this study quantified the potential yields of potatoes without water and fertilizer limitation, and yield under irrigated and rainfed conditions, and the corresponding WUEs across four potato planting regions including the Da Hinggan Mountains (DH), the Foothills of Yanshan hilly (YH), the North foot of the Yinshan Mountains (YM), and the Loess Plateau (LP) in North China.  Simulated average potential potato tuber dry weight yield by the APSIM-Potato Model was 12.4 t ha^–1 for the YH region, 11.4 t ha^–1 for the YM region, 11.2 t ha^–1 for the DH region, and 10.7 t ha^–1 for the LP region, respectively.  Observed rainfed potato tuber dry weight yield accounted for 61, 30, 28 and 24% of the potential yield in the DH, YH, YM, and LP regions.  The maximum WUE of 2.2 kg m^–3 in the YH region, 2.1 kg m^–3 in the DH region, 1.9 kg m^–3 in the YM region and 1.9 kg m^–3 in the LP region was achieved under the potential yield level.  Ridge-furrow planting could boost yield by 8–49% and WUE by 2–36% while ridge-furrow planting with film mulching could boost yield by 35–89% and WUE by 7–57% across North China.  Our study demonstrates that there is a large potential to increase yield and WUE simultaneously by combining ridge-furrow planting with film mulching and supplemental irrigation in different potato planting regions with limited water resources.

Chromatin accessibility plays a vital role in gene transcriptional regulation.  However, the regulatory mechanism of chromatin accessibility, as well as its role in regulating crucial gene expression and kernel development in maize (Zea mays) are poorly understood.  In this study, we isolated a maize kernel mutant designated as defective kernel219 (dek219), which displays opaque endosperm and embryo abortion.  Dek219 encodes the DICER-LIKE1 (DCL1) protein, an essential enzyme in miRNA biogenesis.  Loss of function of Dek219 results in significant reductions in the expression levels of most miRNAs and histone genes.  Further research showed that the Heat shock transcription factor17 (Hsf17)-Zm00001d016571 module may be one of the factors affecting the expression of histone genes.  Assay results for transposase-accessible chromatin sequencing (ATAC-seq) indicated that the chromatin accessibility of dek219 is altered compared with that of wild type (WT), which may regulate the expression of crucial genes in kernel development.  By analyzing differentially expressed genes (DEGs) and differentially accessible chromatin regions (ACRs) between WT and dek219, we identified 119 candidate genes that are regulated by chromatin accessibility, including some reported to be crucial genes for kernel development.  Taken together, these results suggest that Dek219 affects chromatin accessibility and the expression of crucial genes that are required for maize kernel development

The trichomes of rice leaves are formed by the differentiation and development of epidermal cells.  Plant trichomes play an important role in stress resistance and protection against direct ultraviolet irradiation.  However, the development of rice trichomes remains poorly understood.  In this study, we conducted ethylmethane sulfonate (EMS)-mediated mutagenesis on the wild-type (WT) indica rice ‘Xida 1B’.  Phenotypic analysis led to the screening of a mutant that is defective in trichome development, designated lhl1 (less hairy leaf 1).  We performed map-based cloning and localized the mutated gene to the 70-kb interval between the molecular markers V-9 and V-10 on chromosome 2.  The locus LOC_Os02g25230 was identified as the candidate gene by sequencing.  We constructed RNA interference (LHL1-RNAi) and overexpression lines (LHL1-OE) to verity the candidate gene.  The leaves of the LHL1-RNAi lines showed the same trichome developmental defects as the lhl1 mutant, whereas the trichome morphology on the leaf surface of the LHL1-OE lines was similar to that of the WT, although the number of trichomes was significantly higher.  Quantitative real-time PCR (RT-qPCR) analysis revealed that the expression levels of auxin-related genes and positive regulators of trichome development in the lhl1 mutant were down-regulated compared with the WT.  Hormone response analysis revealed that LHL1 expression was affected by auxin.  The results indicate that the influence of LHL1 on trichome development in rice leaves may be associated with an auxin pathway.

Myo-inositol and its derivatives play important roles in the tolerance of higher plants to abiotic stresses, and myo-inositol-1-phosphate synthase (MIPS) is the rate-limiting enzyme in myo-inositol biosynthesis.  In this study, we found that increased myo-inositol biosynthesis enhanced drought tolerance in MdMIPS1-overexpressing apple lines under short-term progressive drought stress.  The effect of myo-inositol appeared to be mediated by the increased accumulation of osmoprotectants such as glucose, sucrose, and proline, and by the increased activities of antioxidant enzymes that eliminate reactive oxygen species.  Moreover, enhanced water-use efficiency (WUE) was observed in MdMIPS1-overexpressing apple lines under long-term moderate water deficit conditions that mimicked the water availability in the soil of the Loess Plateau.  Enhanced WUE may have been associated with the synergistic regulation of osmotic balance and stomatal aperture mediated by increased myo-inositol biosynthesis.  Taken together, our findings shed light on the positive effects of MdMIPS1-mediated myo-inositol biosynthesis on drought tolerance and WUE in apple.

Understanding the genetic basis of quality-related traits contributes to the improvement of grain protein concentration (GPC), grain starch concentration (GSC), and wet gluten concentration (WGC) in wheat, a genome-wide association study (GWAS) based on a mixed linear model (MLM) was performed on the 236 wheat accessions including 160 cultivars and 76 landraces using 55K single nucleotide polymorphism (SNP) array in multiple environments. A total of twelve stable QTL/SNPs were identified to control different quality traits in this populations at least two environments under stripe rust stress; three, seven and two QTLs associated with GPC, GSC, and WGC were characterized respectively and located on chromosomes 1B, 1D, 2A, 2B, 2D, 3B, 3D, 5D, and 7D with the range of phenotypic variation explained (PVE) from 4.2 to 10.7%. Compared with the previously reported QTLs/genes, five QTLs (QGsc.sicau-1BL, QGsc.sicau-1DS, QGsc.sicau-2DL.1, QGsc.sicau-2DL.2, QWgc.sicau-5DL) were potentially novel. KASP markers for SNPs AX-108770574 and AX-108791420 on chromosome on 5D associated with wet gluten concentration were successfully developed. Phenotype of the cultivars containing the A-allele in AX-108770574 and T-allele in AX-108791420 were extremely significantly (P<0.01) higher than that of the landraces containing the G-allele or C-allele of wet gluten concentration in each of the environments. The developed and validated KASP markers could be utilized in molecular breeding aiming to improve the quality in wheat.