Flavonols and flavanones are important bioactive compounds with multiple pharmacological activities and health benefits.  Transcriptional activation of flavonol and flavanone biosynthesis has been studied extensively, while little is known about the negative regulators.  CRISPR/Cas9 gene-editing technology, with the advantage of precise genetic modification, is a desirable tool for breeding biofortified materials and exploring potential molecular mechanisms.  In this study, a transcriptional repressor, SlMYB32, was characterized in tomato fruit.  Phenotype and metabolomic analyses confirmed that knockout of SlMYB32 resulted in increased accumulation of flavonols and flavanones, especially about 1 mg g^–1 FW of quercetin 3-O-rutinoside (rutin).  Transcriptome analysis indicated that expression of key genes SlPAL6, Sl4CL3 and Sl4CL4 as well as five candidate SlUGTs were significantly up-regulated in slmyb32 mutants.  Dual-luciferase and EMSA assays indicated SlMYB32 could bind to and repress promoter activities of SlPAL6 and Sl4CL3.  Expression of 27 transcription factors belonging to 12 families was significantly changed in slmyb32 mutants, among which two SlMYBs, two SlNACs, two SlAP2s and one SlWRKY were clustered with known flavonoid regulators.  Our results provide new insights into improving bioactive compounds in fruit and understanding negative regulatory mechanisms in flavonol and flavanone biosynthesis.

Species closely related to wheat are important genetic resources for agricultural production, functional genomics studies and wheat improvement.  In this study, a wheat gene related to regeneration, TaWOX5, was applied to establish the Agrobacterium-mediated transformation systems of Triticum monococcum, hexaploid triticale, and rye (Secale cereale L.) using their immature embryos.  Transgenic plants were efficiently generated.  During the transformation process, the Agrobacterium infection efficiency was assessed by histochemical staining for β-glucuronidase (GUS).  Finally, the transgenic nature of regenerated plants was verified by polymerase chain reaction (PCR)-based genotyping for the presence of the GUS and bialaphos resistance (bar) genes, histochemical staining for GUS protein, and the QuickStix strip assay for bar protein.  The transformation efficiency of T. monococcum genotype PI428182 was 94.4%; the efficiencies of four hexaploid triticale genotypes Lin456, ZS3297, ZS1257, and ZS3224 were 52.1, 41.2, 19.4, and 16.0%, respectively; and the transformation efficiency of rye cultivar Lanzhou Heimai was 7.8%.  Fluorescence in situ hybridization (FISH) and genomic in situ hybridization (GISH) analyses indicated that the GUS transgenes were integrated into the distal or near centromere (proximal) regions of the chromosomes in transgenic T. monococcum and hexaploid triticale plants.  In the transgenic hexaploid triticale plants, the foreign DNA fragment was randomly integrated into the AABB and RR genomes.  Furthermore, the transgene was almost stably inherited in the next generation by Mendel’s law.  The findings in this study will promote the genetic improvement of the three plant species for grain or forage production and the improvement of cereal species including wheat for functional genomics studies.

Straw return is a promising strategy for managing soil organic carbon (SOC) and improving yield stability.  However, the optimal straw return strategy for sustainable crop production in the wheat (Triticum aestivum L.)–cotton (Gossypium hirsutum L.) cropping system remains uncertain.  The objective of this study was to quantify the long-term (10 years) impact of carbon (C) input on SOC sequestration, soil aggregation and crop yields in a wheat–cotton cropping system in the Yangtze River Valley, China.  Five treatments were arranged with a single-factor randomized design as follows: no straw return (Control), return of wheat straw only (Wt), return of cotton straw only (Ct), return of 50% wheat and 50% cotton straw (Wh-Ch) and return of 100% wheat and 100% cotton straw (Wt-Ct).  In comparison to the Control, the SOC content increased by 8.4 to 20.2% under straw return.  A significant linear positive correlation between SOC sequestration and C input (1.42–7.19 Mg ha⁻¹ yr⁻¹) (P<0.05) was detected.  The percentages of aggregates of sizes >2 and 1–2 mm at the 0–20 cm soil depth were also significantly elevated under straw return, with the greatest increase of the aggregate stability in the Wt-Ct treatment (28.1%).  The average wheat yields increased by 12.4–36.0% and cotton yields increased by 29.4–73.7%, and significantly linear positive correlations were also detected between C input and the yields of wheat and cotton.  The average sustainable yield index (SYI) reached a maximum value of 0.69 when the C input was 7.08 Mg ha⁻¹ yr⁻¹, which was close to the maximum value (SYI of 0.69, C input of 7.19 Mg ha⁻¹ yr^–1) in the Wt-Ct treatment.  Overall, the return of both wheat and cotton straw was the best strategy for improving SOC sequestration, soil aggregation, yields and their sustainability in the wheat–cotton rotation system.

Wheat (Triticum aestivum L.) is one of the most important food crops globally, and its flour can be processed into a wide variety of foods.  The high-molecular-weight glutenin subunits (HMW-GSs) play a crucial role in determining the flour-processing quality.  In this study, we used the CRISPR/Cas9 system to generate eight types of wheat mutants with the silencing of one to four HMW-GS-encoding genes simultaneously.  These mutations were identified in the T₁ generation by PCR-restriction enzyme (PCR-RE) analysis and sequencing.  In the T₂ generation, mutants were confirmed to express one to four HMW-GSs by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and ultra-high-performance liquid chromatography (UPLC).  Phenotypic analysis showed that the mutants were comparable to the wild-type (WT) in terms of major agronomic and grain traits.  However, glutenin macropolymers (GMP) content in the mutants was significantly lower than in the WT.  Transmission electron microscopy (TEM) revealed a flaky GMP structure in the mutant grain endosperms, indicating that the absence of HMW-GSs did not affect GMP formation. SDS-sedimentation volume (SDS-SV) and bread-baking tests revealed that the contribution of HMW-GSs to processing quality was ranked as 1Dx5>1Dy12>1Ax1 in the genetic background of CB037.  Interestingly, although bread-baking quality deteriorated, the cookie-making and noodle quality of the mutants improved.  The cookie made from the dDx mutant had the thinnest, largest diameter, and the highest spread factor.  Mutants with reduced HMW-GS content may provide a new strategy for wheat breeding tailored for cookie and noodle production.

Leaf angle critically influences maize canopy structure and yield. NAC transcription factors regulate various developmental processes, yet their role in maize leaf angle remains poorly understood. In this study, we demonstrate that modulating the expression level of ZmNF-YC13 significantly alters the expression of ZmNAC118, suggesting that these two genes likely function within a common regulatory pathway. ZmNAC118 shows preferential expression in leaf tissues and encodes a nuclear-localized protein capable of transcriptional activation. Phenotypic analyses demonstrated that overexpression of ZmNAC118 leads to a pronounced reduction in auricle size and leaf angle. Transcriptomic profiling further revealed that ZmNAC118 modulates the expression of CYP450 genes associated with brassinosteroid (BR) and auxin (IAA) metabolic pathways. These CYP450 genes clustered into hormone-related phylogenetic clades, with a subset overlapping targets of ZmNF-YC13, indicating co-regulation within a shared pathway. Our study identifies ZmNAC118 as a key regulator of leaf angle and a promising candidate for maize architectural improvement.