Phosphorus (P) availability influences the spatial distribution of carbon (C)-cycling enzyme activities in the rhizosphere through its effects on plant growth and microbial activity.  However, the influence of P availability on the spatial patterns of C and P hydrolase activities remains unclear in the rhizosphere of Maize (Zea mays L.) and narrow-leaf lupine (Lupinus angustifolius L.), which exhibit contrasting P deficiency adaptation and acquisition strategies.  This study analyzed the spatial patterns of C and P hydrolase activities through zymography and correlated them with bacterial community structure in maize and lupine rhizospheres.  Under P-deficient conditions, maize exhibited severe growth restriction while demonstrating a 2.2–9.6-fold increase in root exudation compared to P-sufficient conditions.  The enhanced exudation under P deficiency promoted r-strategist bacterial proliferation (e.g., Ktedonobacteria and Xanthomonadales) while reducing K-strategist abundance (Actinobacteriota, Chloroflexia, and Alphaproteobacteria).  Maize rhizosphere enzyme activities and hotspot areas demonstrated positive correlation with K-strategist abundance and negative correlation with r-strategist abundance.  P-sufficient maize exhibited 15–550% higher C- and P-cycle-related enzyme activity and hotspot areas, attributed to its enhanced root system and predominance of K-strategists with superior enzyme synthesis capabilities.  Lupine demonstrated superior P deficiency adaptation, producing 2–19 times more DOC and organic acids than maize.  Consequently, lupine showed no significant alterations in enzyme activity, hotspot areas, or bacterial community composition in response to P availability.  These findings demonstrate that plant-specific P deficiency adaptation mechanisms distinctly influence the spatial distribution of C-cycling enzyme activity and bacterial community structure in the rhizosphere.

Climate disasters lead to substantial economic losses and grain yield losses, emphasizing the need for adaptation to ensure food security.  As digital technologies advance, it is imperative to investigate how digital literacy among grain farmers affects their adaptive production behaviors in the face of climate disasters.  Drawing on survey data from 505 grain-producing smallholders in Sichuan Province, China, this study constructs a theoretical framework linking digital literacy, climate disaster risk perception, and adaptive production behaviors.  Empirical analysis shows that digital literacy positively impacts the adaptive production behaviors of grain-producing smallholders.  Our results are robust across various models and tests.  An analysis of the mediation mechanism reveals that digital literacy contributes to climate disaster-adaptive production behaviors by improving the awareness of climate disaster risks.  Heterogeneity analysis shows that the positive impact of digital literacy is more pronounced for smallholders that receive internet skills training and climate information services, and this impact intensifies as the level of agricultural infrastructure improves.  The findings suggest that digital literacy plays a key role in reducing production risks, thereby contributing to increased sustainable agricultural development among smallholders.

Introducing the inherent genetic diversity of wild species into cultivars has become one of the hot topics in crop genetic breeding and genetic resource research.  Fiber- and seed-related traits, which are critical to the global economy and people’s livelihoods, are the principal focus of cotton breeding.  Here, the wild cotton species Gossypium tomentosum was used to broaden the genetic basis of G. hirsutum and identify QTLs for fiber- and seed-related traits.  A population of 559 chromosome segment substitution lines (CSSLs) was established with various chromosome segments from G. tomentosum in a G. hirsutum cultivar background.  Totals of 72, 89, and 76 QTLs were identified for three yield traits, five fiber quality traits, and six cottonseed nutrient quality traits, respectively.  Favorable alleles of 104 QTLs were contributed by G. tomentosum.  Sixty-four QTLs were identified in two or more environments, and candidate genes for three of them were further identified.  The results of this study contribute to further studies on the genetic basis of the morphogenesis of these economic traits, and indicate the great breeding potential of G. tomentosum for improving the fiber- and seed-related traits in G. hirsutum.

Unbalanced fertilizer application with high intensity nitrogen (N) and insufficient potassium (K) results in declining soil fertility.  Balanced fertilization represents an effective approach to reduce fertilizer usage while enhancing maize yield and efficiency.  This study examined two N levels (180 and 225 kg N ha⁻¹, abbreviated N12 and N15) and four K treatments (0, 75, 150, and 75+75 kg K₂O ha⁻¹, abbreviated K0, K5, K10, and K5+5) to investigate the effects of combined N and K application on biomass, nutrient accumulation, and remobilization characteristics in waxy maize.  Results indicated that grain yield increased with higher K application at constant N levels, demonstrating an average increase of 1,254.8 kg ha⁻¹ (2020) and 727.3 kg ha⁻¹ (2021) compared with K0.  Under identical N and K applications, K5+5 enhanced grain yield through increased kernel weight.  The K5+5 treatment showed no significant difference in biomass and nutrient accumulation between N12 and N15.  Compared to K10, K5+5 enhanced both the average remobilization amount (RBA) of biomass and increased RBA of N, phosphorus (P) and K.  Additionally, the average remobilization efficiency (RBE) of biomass, N, P, and K in K5+5 increased by 3.3, 4.6, 10.6, and 4.2%, respectively.  Moreover, topdressing K improved the apparent contribution to grain (AC) of biomass, N, P and K, facilitating greater nutrient transfer to grains and significantly increasing nutrient harvest index.  Based on yield and fertilizer use efficiency, this study recommends optimized K application (basal and topdressing 75 kg ha⁻¹) and moderate reduction in N application (from 225 to 180 kg ha⁻¹) for spring-sown waxy maize production in southern China.

Modern rice production faces the dual challenges of increasing grain yields while reducing inputs of chemical fertilizer.  However, the disequilibrium between the nitrogen (N) supplement from the soil and the demand for N of plants is a serious obstacle to achieving these goals.  Plant-based diagnosis can help farmers make better choices regarding the timing and amount of topdressing N fertilizer.  Our objective was to evaluate a non-destructive assessment of rice N demands based on the relative SPAD value (RSPAD) due to leaf positional differences.  In this study, two field experiments were conducted, including a field experiment of different N rates (Exp. I) and an experiment to evaluate the new strategy of nitrogen-split application based on RSPAD (Exp. II).  The results showed that higher N inputs significantly increased grain yield in modern high yielding super rice, but at the expense of lower nitrogen use efficiency (NUE).  The N nutrition index (NNI) can adequately differentiate situations of excessive, optimal, and insufficient N nutrition in rice, and the optimal N rate for modern high yielding rice is higher than conventional cultivars.  The RSPAD is calculated as the SPAD value of the top fully expanded leaf vs. the value of the third leaf, which takes into account the non-uniform N distribution within a canopy.  The RSPAD can be used as an indicator for higher yield and NUE, and guide better management of N fertilizer application.  Furthermore, we developed a new strategy of nitrogen-split application based on RSPAD, in which the N rate was reduced by 18.7%, yield was increased by 1.7%, and the agronomic N use efficiency was increased by 27.8%, when compared with standard farmers’ practices.  This strategy of N fertilization shows great potential for ensuring high yielding and improving NUE at lower N inputs.

Ferroptosis is the primary form of regulated cell death in cashmere goat sperm during the freeze-thaw process, which significantly hinders the efficacy and application of frozen semen technology, yet its specific regulatory mechanisms remain unclear. Here, we found it activated during the cooling-equilibration phase, linked to the degradation of critical ferroptosis inhibitory proteins like ferritin heavy chain 1 (FTH1). Freezing causes superoxide anion accumulation via cytochrome b (CYTB) upregulation and reduced mitochondrial antioxidants, unblocked by ferrostatin-1 (Fer-1). Superoxide anions dose-dependently induce ferroptosis, mitigated by Fer-1. Autophagy/ferritinophagy inhibitors alleviate it, implicating ferritinophagy. This identifies superoxide anions as key mediators, offering new targets for sperm cryopreservation.

Although jasmonate (JA) signaling participates in heat stress (HS) responses, the mechanism by which it balances spikelet development and yield stability via the OsCOI1 gene remains unclear, particularly under HS during the panicle differentiation stage (PDS). This study comprehensively examined the influence of HS on panicle architecture, carbon (C) and nitrogen (N) metabolism, accumulation and allocation, root oxidative activity, antioxidant enzyme activity, JA and methyl jasmonate (MeJA) contents, yield and yield components using wild-type rice (WT, Nipponbare) and the coi1-18 mutant (OsCOI1 knockdown mutant, blocked JA signaling). The results demonstrated that under normal temperature (NT) conditions, the coi1-18 mutant exhibited significantly higher grain number per panicle, grain setting rate, and 1000-grain weight relative to the WT, collectively increasing grain yield by 23.2%. Conversely, under HS, reduced JA and MeJA contents in the coi1-18 mutant resulted in enhanced heat sensitivity, diminished antioxidant capacity, and dysregulated C-N metabolism. These effects markedly suppressed spikelet differentiation, thereby causing a yield reduction in the coi1-18 mutant that was 16.1 percentage points greater than in WT. Exogenous MeJA application effectively mitigated HS-induced suppression of spikelets differentiation in WT but failed to significantly rescue the phenotype in the coi1-18 mutant. This study reveals OsCOI1 as a context-dependent regulator: knockdown of OsCOI1 enhances yield under NT but impairs HS tolerance during PDS. This indicates a breeding-relevant trade-off and suggests that modulating JA signaling could balance yield under NT with panicle protection under HS.

To address the dual challenges of water scarcity and rising demand for premium rice, this study investigated the synergistic effects of mild alternate wetting and drying (Mild AWD) irrigation combined with wheat straw biochar application on rice yield and grain quality. A two-year field experiment (2023–2024) was conducted with the hybrid rice cultivar Yongyou 2640, with two irrigation regimes: continuous flooding (CF) and Mild AWD (re-irrigation at a soil water potential of −10 to −15 kPa at 15–20 cm depth), with or without a one-time biochar application (10 t ha^-1). The results showed that co-application of Mild AWD and biochar significantly increased grain yield by 18.7% in 2023 and 13.4% in 2024 compared to CF alone. It also comprehensively improved grain quality: milling quality (head rice rate increased by 23.1–24.6%), appearance quality (chalkiness reduced by 36.4–38.2%), cooking and eating quality (higher peak viscosity, lower gelatinization temperature and enthalpy), and nutritional quality (increased glutelin and decreased prolamin content and starch digestion). These improvements were attributed to enhanced root activity alongside leaf photosynthetic rate, which promotes the accumulation of photoassimilates in vegetative organs and their translocation to grains. Moreover, elevated activities of key starch synthases further enhanced starch biosynthesis and accumulation, which underpinned the improved yield and superior quality. We also identified that a minimum soil water potential of −10 to −15 kPa at a depth of 15–20 cm represents the optimal threshold for mild AWD in rice production. This research provides a cultivation approach for synergistically producing high-yield, high-quality rice, which shows promising potential for scalable implementation.

This study explored the effects of a wetting alternating with mild drying (WMD) management strategy, on rice productivity and methane (CH₄) emissions, and its underlying mechanisms. A high-yielding hybrid rice cultivar was grown in field trials under either conventional irrigation (CI) or the WMD regimen from transplanting to maturity. Results revealed that the WMD approach significantly boosted grain yield while simultaneously reducing CH₄ emissions. It was accompanied by a slight increase in nitrous oxide (N₂O) emissions versus CI. However, the mitigation benefits of decreased CH₄ emissions in lowering global warming potential (GWP) and greenhouse-gas intensity (GHGI) outweighed the adverse contributions of elevated N₂O emissions. Elevated BR levels in roots enhanced antioxidant defense through the ascorbate-glutathione cycle pathway, which reduced ROS accumulation, thereby not only maintaining root activity but also suppressing root aerenchyma formation—ultimately restricting CH₄ transport pathways under WMD regime. Furthermore, the increased root BR levels suppressed CH₄ production by directly or indirectly inhibiting the mcrA gene abundance, while promoting CH₄ oxidation through rhizosphere exudates enriched with specific organic acids that stimulated the pmoA gene abundance in paddy soil. Under the WMD regime, BR-induced enhancement of root activity significantly boosted photosynthetic capacity, establishing a positive feedback loop that promoted assimilate accumulation. Concurrently, WMD facilitated photosynthate allocation from vegetative tissues to grains, collectively improving rice yield. Collectively, our data suggest that the WMD practices can effectively reduce CH₄ emissions, GWP, and GHGI in rice paddies while maintaining high grain yield by stimulating root-derived BR biosynthesis.

Soil alkalization, driven by bicarbonate stress, severely inhibits soybean (Glycine max L.) seed germination. While spermidine (Spd) is known to enhance plant tolerance to abiotic stress, whether and how it alleviates bicarbonate stress remains unclear. Here, we demonstrate that Spd treatment significantly alleviates bicarbonate stress experienced by in germinating soybeans, as evidenced by higher germination rates and greater root biomass. Physiological assays revealed that Spd diminishes accumulation of reactive oxygen species accumulation and malondialdehyde while promoting proline accumulation. Transcriptome and weighted gene co-expression network analysis (WGCNA) indicated that Spd continuously upregulates genes in the phenylpropanoid and flavonoid biosynthesis pathways in germinating seeds. Two key genes in these pathways, GmPAL1.1 (Phenylalanine Ammonia-Lyase 1.1) and GmCCR1 (Cinnamoyl-CoA Reductase 1), are associated with seed germination. Furthermore, natural variation in GmPAL1.1 and GmCCR1 is associated with adaptation to saline-alkaline soils: the elite haplotypes GmPAL1.1-Hap1 and GmCCR1-Hap3 are associated with favorable agronomic traits and improved adaptation to these soils. These findings reveal that Spd enhances bicarbonate tolerance by coordinating antioxidant defense mechanisms and activating the phenylpropanoid and flavonoid biosynthesis pathways. In addition, our results identify GmPAL1.1 and GmCCR1 as potential elite genes for breeding alkaline-tolerant soybean cultivars.