Tillage practices alter the interaction between soil and rice straw, impacting soil quality and cadmium (Cd) dynamics.  However, the effects of tillage and straw management strategies on soil Cd accumulation and rice uptake remain unclear.  This study investigated how tillage and straw practices influence rice Cd uptake by altering soil Cd mobility and bioavailability.  A long-term field experiment was conducted with four treatments: no-tillage with straw return on the soil surface (NTS), rotary tillage with straw incorporation (RTS), plow tillage with straw incorporation (PTS), and plow tillage with straw removed (PT).  Results showed that Cd concentrations in rice organs (root, stem, leaf, and rice grain) decreased in the order NTS>RTS>PTS, with only PTS maintaining grain Cd levels below 0.2 mg kg^–1.  Compared with NTS and RTS, the average Cd concentrations in rice grain under PTS were significantly reduced by 56.76 and 25.88%, respectively.  A partial least squares path model indicated that reductions in available Cd (Avail-Cd) and acid-soluble Cd (Aci-Cd), combined with iron plaque (IP) formation on the roots, were key factors in lowering rice Cd levels.  PTS reduced Avail-Cd and Aci-Cd by decreasing soil bulk density, increasing soil organic matter, pH, and the abundances of Nitrospirota and Bacteroidota.  Moreover, PTS enhanced soil nutrient and Fe²⁺ levels, promoted IP formation on rice roots through improved root morphology and antioxidant activity, and limited Cd uptake.  Although PTS increased total and available soil Cd compared to PT, its promotion of IP formation mitigated rice Cd uptake, resulting in comparable grain Cd concentrations between the two.  Thus, long-term plow tillage with straw incorporation emerges as a sustainable practice to enhance soil quality and reduce Cd uptake in the rice cropping system.

Enhancing wheat grain weight is a crucial strategy for improving yields in the Huaibei Plain (HP), China.  However, the impacts and regulatory mechanisms of different irrigation regimes on wheat grain formation in the HP remained poorly understood.  Therefore, a two-year field experiment was conducted to explore three treatments on wheat’s source–sink relationship and grain formation: rain-fed (RI, no irrigation, 202.5 kg ha^–1 N applied at sowing), conventional flood irrigation (CI, 60 mm irrigation at jointing stage, 112.5 kg ha^–1 N at sowing+90 kg ha^–1 N with irrigation), and micro-sprinkler irrigation (MI, irrigation based on 0–40 cm soil layer water deficit at jointing, booting and anthesis stages, 112.5 kg ha^–1 N at sowing+30 kg ha^–1 N at each irrigation).  The results indicated that, compared with RI and CI, MI significantly increased chlorophyll content and enhanced sucrose phosphate synthase (SPS) activity in the flag leaf at 4 days after anthesis (DAA 4), and these parameters in CI were higher than those in RI.  The sucrose and soluble sugar content in the grain of MI were the highest at DAA 4.  Additionally, at DAA 4, compared with RI, both CI and MI significantly elevated the content of indole propionic acid+zeatin nucleoside (IPA+ZR) and gibberellin (GA) in grain, while reducing the content of auxin (IAA) and abscisic acid (ABA).  And the highest number of endosperm cells was observed in MI.  At the grain-filling stage, MI exhibited the slowest chlorophyll degradation rate and the highest activities of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and SPS in the flag leaf, resulting in more sugar accumulation in the leaf and grain.  Moreover, MI showed the highest IAA and lowest ABA levels in grain and maintained the highest starch synthase activity during the filling stage, thereby promoting starch accumulation.  Compared to CI and RI, MI significantly increased 1,000-grain weight by 4.99–5.55% and 7.33–11.51%, and grain yield by 4.99–11.60% and 15.60–39.14% over the two years, respectively.  Overall, micro-sprinkler irrigation can optimize the water and nitrogen supply for wheat, effectively enhancing the source capacity in the early stage and the sink capacity in the late stage of grain development, thereby increasing grain weight and achieving high yield in the HP.

Traditional two-dimensional (2D) analyses of maize (Zea mays L.) plant shape plasticity and canopy transmission under varying planting densities have limitations in capturing spatial heterogeneity.  This study used a three-dimensional (3D) phenotyping platform to investigate architectural plasticity across different maize varieties and planting densities.  Seven novel 3D architectural parameters were developed, and 3D canopy models were constructed for light distribution simulation.  At the vegetative stage 9 (V9) stage, medium planting density (67,500 plants ha^–1, MD) increased plant side width and convex hull volume by 7.2 and 11.4%, respectively, compared to low planting density (37,500 plants ha^–1, LD).  High planting density (97,500 plants ha^–1, HD) increased the width and volume by 4.2 and 17.8%, respectively, compared with MD.  Similar changes were maintained at the V13 stage.  At the silking stage, the number of voxel volume plant (NVP) and projected area (PJA) decreased by 6.2 and 11.9%, respectively, under MD compared with LD, and by 4.9 and 3.6%, respectively, under HD compared with MD.  Across all densities, PJA and NVP in both MC812 and JNK728 were consistently lower than in ZD958.  A bottom light transmittance estimation model combining point cloud parameters with support vector regression achieved reliable predictions (R²=0.76, RMSE=2.89%).  The 3D canopy model effectively simulated population light distribution (R²=0.83, RMSE=8.53%).  NVP and PJA were identified as critical parameters affecting bottom canopy transmittance, suggesting their potential as 3D selection indices for maize density tolerance breeding.  These findings provide insights into stage-specific architectural plasticity and light interception, supporting molecular design breeding of density-tolerant maize.

High temperature (HT) is a critical abiotic stress factor that negatively impacts yield and quality of maize worldwide.  Although the effects of HT during key growth stages are extensively documented, the distinct influences of daytime versus nighttime HT on the physicochemical properties of waxy maize starch remain largely unexplored.  This study investigated the effects of daytime and nighttime HT on the on the starch physicochemical properties in two waxy maize hybirds.  Temperature treatments included ambient temperature (NN), daytime HT (DH), nighttime HT (NH), and whole-day HT (DNH), which were applied from 1 to 15 days after pollination.  The three HT stresses significantly inhibited starch synthesis and accumulation, increased the number of pores on the starch granule surface, enlarged starch granule size, enhanced relative crystallinity, and shortened the chain length and reduced the branching degree of amylopectin.  The most severe effects were observed under DNH, followed by DH.  DH and DNH reduced starch pasting viscosity and gelatinization enthalpy while increasing starch retrogradation through mechanisms involving enlargement of granule size, increased relative crystallinity, and reduced branching and chain length of amylopectin.  NH increased gelatinization enthalpy and retrogradation and decreased starch pasting viscosity primarily by shortening the chain length of amylopectin.  By elucidating the mechanisms through which daytime and nighttime HT affect starch physicochemical properties, this study provides valuable insights into optimizing waxy maize production in response to climate change challenges.

Loquat (Eriobotrya japonica) is an evergreen fruit tree native to China, with a flowering period that typically occurs in winter (October to January), making it vulnerable to low-temperature stress during critical reproductive stages.  However, the molecular mechanisms underlying cold tolerance in loquat remain largely unclear.  In this study, transcriptome data from multiple loquat cultivars were analyzed using Weighted Gene Co-expression Network Analysis (WGCNA), identifying two gene modules (brown and turquoise modules) highly associated with cold treatment.  Among the cold-responsive candidates, the Rab5 family GTPase EjRabF2b was consistently upregulated under low-temperature conditions.  Functional validation revealed that overexpression of EjRabF2b in Arabidopsis thaliana and tomato significantly enhanced cold tolerance, while its silencing in loquat compromised stress resistance.  Mechanistically, EjRabF2b contributed to maintaining cell membrane integrity and enhancing antioxidant enzyme activity.  Promoter analysis and interaction assays further confirmed that the C2H2-type transcription factor EjZAT10 directly binds to the promoter of EjRabF2b and activates its transcription under cold stress.  Collectively, this study uncovers a regulatory module composed of EjZAT10 and EjRabF2b that participates in loquat cold adaptation through vesicle-mediated antioxidant defense and membrane protection, offering a theoretical foundation and potential targets for the molecular breeding of cold-tolerant cultivars.

Soil salinization is a growing challenge for highbush blueberry (Vaccinium corymbosum) production, but knowledge about its physiological and molecular responses to salt stress remains limited.  To address this, we performed Gene Ontology (GO) enrichment analysis and weighted gene co-expression network analysis (WGCNA) on differentially expressed genes from the roots and leaves of the salt-tolerant cultivar ‘Duke’ and the salt-sensitive cultivar ‘Sweetheart’.  GO analysis revealed significant enrichment of ion transport and cellular ion homeostasis in the roots under salt stress.  WGCNA identified a strong correlation between Na⁺ and K⁺ contents and the expression of hub genes VcHAK5, VcNHX1, and VcNHX2 under salt stress.  These genes were significantly upregulated in the roots of the salt-tolerant cultivar.  VcHAK5 encodes a K⁺-selective ion transporter in the plasma membrane, and VcNHX1 and VcNHX2 encode Na⁺/H⁺ and K⁺/H⁺ antiporters in the tonoplast.  Knockdown mutants of these genes in blueberry calli showed hypersensitivity to salt stress.  Furthermore, reciprocal grafting between salt-sensitive and salt-tolerant blueberry cultivars demonstrated that lower root Na⁺ content and Na⁺/K⁺ ratios are crucial for salt tolerance.  This study provides the first comprehensive insights into blueberry responses to salt stress, identifies target genes and highlights the critical role of salt-resistant roots.

Global climate warming and extreme high-temperature events significantly impact crop growth, development, and economic productivity.  Plants typically enhance heat tolerance by regulating heat shock transcription factors (HSFs) and antioxidant enzymes to reduce the detrimental impacts of heat stress.  However, the precise regulatory mechanisms by which HSFs confer heat tolerance in tomato remain to be elucidated.  In this study, we investigated the role of the heat-induced transcription factor SlHSFA3 in tomato heat tolerance.  We demonstrated that knockout of SlHSFA3 increases tomato plants’ sensitivity to heat stress, while enhanced expression of SlHSFA3 improves heat tolerance by promoting reactive oxygen species (ROS) scavenging through increased ascorbate peroxidase (APX) activity.  Similarly, overexpression of SlAPX1 enhances heat tolerance in tomato by reducing ROS accumulation, whereas its knockout increases heat stress sensitivity.  Furthermore, SlHSFA3 interacts with SlAPX1 to further augment APX activity.  Molecular analysis revealed that SlHSFA3 directly upregulates the expression of SlAPX1 by binding to its promoter region.  In summary, our findings elucidate the molecular mechanism of the SlHSFA3-SlAPX1 regulatory pathway in tomato heat tolerance, providing a theoretical foundation for developing advanced biotechnological and breeding strategies to improve crop adaptation under elevated temperature conditions.

The type A protein phosphatase 2C (PP2C-A) gene family is vital for regulating the ABA signaling pathway and plant stress responses.  In this research, 14 SlPP2C-A genes were identified in the tomato genome, distributed across six chromosomes.  Most SlPP2C-A genes contain cis-acting elements associated with growth, development, light, hormones, and stress responses.  Collinearity analysis revealed high homology between the tomato and Arabidopsis PP2C-A gene families.  Tissue-specific expression analysis indicated that SlPP2C7 is highly expressed in flowers, leaves, and mature fruits, and is significantly induced by saline-alkali stress.  Gene-edited SlPP2C7 knockout mutants subjected to saline-alkali stress confirmed that SlPP2C7 negatively regulates saline-alkali tolerance in tomato.  Combined transcriptomic and metabolomic analyses showed that under saline-alkali stress, metabolic pathways such as flavonoid biosynthesis, isoflavonoid biosynthesis, flavone and flavonol biosynthesis, phenylpropanoid biosynthesis, and phenylalanine metabolism were significantly enriched.  These outcomes imply that SlPP2C7 may enhance tolerance to saline-alkali stress through modulating flavonoid biosynthesis pathways.  This research reveals comprehension of the physiological and molecular mechanism responsible for saline-alkali stress tolerance mediated by SlPP2C7 in tomato.

Potato is a vital global food source, yet the metabolic and transcriptional regulation governing tuber development and quality remains poorly understood.  Here, we performed integrated metabolomic and transcriptomic analyses in wild and cultivated potato tubers, revealing dynamic and distinct metabolic accumulation patterns.  The 849 metabolites exhibited 10 distinct temporal accumulation patterns, including six shared patterns between accessions and four genotype-specific patterns.  The wild genotype exhibited an early decrease in lipids, followed by an increase in phenolic acids, whereas the cultivated genotype displayed an early increase in phenolic acids, accompanied by a decrease in some phenolic acids, amino acids, and flavonoids.  A comparative analysis highlighted the cultivated genotype exhibited significantly lower levels of bitter steroidal glycoalkaloids (SGAs) but higher levels of beneficial flavonoids compared with its wild relative.  Co-expression network analysis revealed 35 SGA-related and 57 phenylpropanoid-related genes that underlie metabolite dynamics.  Notably, we functionally validated that the transcription factor StMYB113 plays a previously unknown role in positively regulating phenolic acid biosynthesis in tuber flesh.  Our work provides a comprehensive map of tuber metabolism and a valuable resource for accelerating the genetic improvement of key potato quality traits.

Waterlogging poses a major challenge to Welsh onion (Allium fistulosum L.) production, exacerbated by climate change-induced extreme weather.  Unraveling the molecular mechanisms of waterlogging tolerance is essential for breeding resilient cultivars.  Here, we compared two Welsh onion varieties: BJQC (tolerant) and YZDC (sensitive).  Waterlogging treatment revealed that YZDC exhibited higher accumulation of reactive oxygen species (ROS), including hydrogen peroxide (H₂O₂), superoxide ions (O₂^–·), and malondialdehyde (MDA), leading to increased mortality.  In contrast, BJQC demonstrated enhanced waterlogging tolerance, which was attributed to its ability to upregulate flavonoid biosynthesis genes, resulting in higher flavonoid accumulation under waterlogging stress.  Transcriptomic analysis identified that the activation of flavonoid pathway-related genes in BJQC was central to this response.  In addition, genes associated with jasmonic acid and gibberellin signaling were activated.  Weighted gene co-expression network analysis (WGCNA) revealed that WRKY31 and MATE likely played critical roles in regulating flavonoid biosynthesis under waterlogging conditions.  Genome-wide association study (GWAS) results from natural populations further supported the significance of these genes in waterlogging tolerance.  Our comprehensive multi-omics analysis, including phenotypic, physiological, transcriptomic, and genomic approaches, provided new insights into the molecular mechanisms underlying Welsh onion responses to waterlogging.  These findings highlight WRKY31 and MATE as key candidates for improving waterlogging tolerance in crop breeding programs.