2026-04-02
Prerana Upretee, Manjula S. Bandara, Randy W. Purves, Yongfeng Ai, Lawrence V. Gusta, Karen K. Tanino
Late fall seeding (aka dormant seeding) can offer significant benefits over spring seeding, including earlier crop maturity, increased grain yield, and reduced risk of frost damage. However, this practice in Western Canada has not yet been adopted due to failures of canola crop establishment the following spring. A series of experiments was conducted on lentil (Lens culinaris Medik.) seeds to identify which characteristics are associated with winter survival and freezing tolerance. The lentil crop was used as a model system due to its variation in seed characteristics. We evaluated 38 genotypes for water uptake at +2 °C and freezing tolerance (LT50, LD50). Seed characteristics, including thousand-seed weight (TSW), surface area, volume, coat thickness, starch, protein and phenolic content, were quantified to determine their impact on water uptake and freezing tolerance. The total water uptake amount was positively and linearly correlated with TSW, seed surface area, volume and starch content, whereas it was negatively correlated with protein and phenolic content. Seeds that were frozen after imbibition exhibited lower germination percentages than seeds frozen without prior imbibition, indicating increased hydration is a key factor contributing to the loss of freezing tolerance. These findings suggest that seed morphological traits and biochemical composition modulate freezing tolerance primarily through their influence on water uptake dynamics. This research may help improve winter survival of fall-seeded spring crops, such as lentils, enabling a shift from conventional spring planting to late-fall seeding, potentially transforming crop establishment practice on the semi-arid Canadian prairies.
DOI: 10.3389/fpls.2026.18025662026-04-02
Chongqin Luo, Fusen Yang, Yuhong Pu, Yanxia Kang, Yanlin Ma, Guangping Qi, Chungang Jing, Huile Lv, Haiyan Li, Yuanbo Jiang, Mingzhu Wang
AbstractGoji berry planting in arid saline-alkali areas faces the challenges of soil micro-ecological imbalance and excessive application of nitrogen fertilizer. ObjectivesTo clarify the interactive effects of different planting patterns and nitrogen application levels on the structure, diversity and function of soil microbial communities in the root zone of goji berry in arid saline-alkali areas, which is of great significance for optimizing the planting system of goji berry in this area and reducing nitrogen application rates and improving nitrogen use efficiency. MethodsBased on field experiments, this study set up two planting patterns: goji berry monoculture and goji–alfalfa intercropping, four nitrogen application gradients: 0 kg·hm-² (N0), 150 kg·hm-² (N1), 300 kg·hm-² (N2), and 450 kg·hm-² (N3). The culturable microbial counts, community structure, diversity and functional genes of bacteria and fungi were analyzed by dilution coating plate method, high-throughput sequencing and functional prediction. Results: Compared with monoculture, the abundances of culturable soil bacteria and actinomycetes were significantly increased under the goji–alfalfa intercropping pattern, while the abundance of culturable fungi and the relative abundance of potential pathogens were inhibited, and the bacterial community structure was optimized. For example, the relative abundance of Proteobacteria decreased, and the proportion of Gemmatimonadota, Actinomycetota and Thermomicrobiota, increased. Diversity analysis showed that N1 treatment was beneficial to maintain the diversity and stability of bacterial and fungal communities in the goji-alfalfa pattern, while N3 treatment significantly inhibited microbial diversity in the goji berry monoculture pattern. The functional prediction showed that the function of bacteria was mainly amino acid metabolism and carbohydrate metabolism. The ILN1 treatment appeared to facilitate the transformation of fungi to mixed trophic strategies such as endophyte-plant pathogens, while the goji berry monoculture pattern tended to rely more heavily on saprophytic nutrition.ConclusionsIn the arid saline-alkali area, the nitrogen reduction management mode of goji-alfalfa intercropping with 150 kg·hm-² could effectively reconstruct the microbial community in the root zone of goji berry. It is a suitable cultivation and nitrogen application management mode for the green and sustainable development of goji berry industry in this area.
DOI: 10.3389/fpls.2026.17936322026-04-02
Guoji Wang, Duo Zhao, Xiaoyu Hu, Haowei Zheng, Wei Wang, Pengyu Bai, Long Miao, Huihui Gao, Longlong Wang, Hongye Sun, Jiajia Li
100-seed weight (100-SW) is a critical determinant of soybean yield. The identification and functional characterization of its underlying genes are therefore essential for the genetic improvement of seed and yield-related traits. A residual heterozygous line (RHL) segregating for 100-SW was derived from a recombinant inbred line (RIL) population generated by crossing small-seed (19.75 ± 1.93 g) and large-seed (26.20 ± 0.82 g) soybean parents. Phenotypic segregation of 100-SW was analyzed, and Chi-square test was used to verify the segregation ratio. Bulked segregant analysis combined with whole-genome sequencing (BSA-seq) was performed using both Euclidean distance and index algorithms to map the target gene. Functional annotation, molecular marker validation, and germplasm resequencing were conducted to identify the key candidate gene and its haplotypes. Phenotypic analysis showed significant segregation and normal distribution of 100-SW in the RHL, with a Chi-square-verified 1:2:1 segregation ratio, indicating control by a single nuclear gene. BSA-seq mapped the gene to a 5.46 Mb region on chromosome 19, where 74 non-synonymous SNPs in coding sequences were identified (including one causing initiation codon loss), distributed across 36 genes. GmDt1 (Glycine max Determinant stem 1) was confirmed as the key candidate gene, with a G-to-T non-synonymous mutation in its first exon as the functional locus (validated in the original RIL population). Resequencing of diverse germplasm classified GmDt1 into five haplotypes; the large-seed haplotype GmDt1-H2 was absent in wild soybeans, present in 9.07% of landraces, and 15.83% of cultivated soybeans. The gradual increase in the frequency of GmDt1-H2 from wild to cultivated soybeans suggests that this haplotype has been positively selected during soybean breeding. Identification of GmDt1 and its functional mutation provides a valuable molecular target for the genetic improvement of soybean seed traits and yield.
DOI: 10.3389/fpls.2026.18019202026-04-02
Natalie J Graham, Gancho Slavov, Steve A. Wakelin, Jaroslav Klápště, Nicola J. Day
IntroductionBoth evolutionary history and recent breeding selections can influence plant microbiomes, with closely-related individuals often having more similar microbiomes. Pinus radiata D.Don is an emerging conifer model species for investigating tree-microbiome interactions. However, little is known about how the P. radiata microbiome covaries with host genotype, especially beyond the seedling stage. MethodsWe sampled the root microbiome of 528 individual P. radiata trees (age = 9 yrs), comprising four clonal copies each of 132 host genotypes from 28 full-sib families, from a clonal breeding trial in New Zealand. We determined whether variations in the bacterial and fungal root microbiomes were associated with host ancestry (i.e., provenance), family, and genotype.ResultsHost family was associated with fungal but not bacterial root microbiome composition, whereas broader ancestry and individual genotype within families had no detectable effect on either bacterial or fungal microbiome composition. While core (in ≥80% samples) amplicon sequence variants (ASVs) typically had negligible heritability, the relative abundances of 83 bacterial and 13 fungal non-core ASVs had low to moderate broad-sense heritabilities (0.2 to 0.46). Host genetic effects associated with abundances of heritable ASVs were primarily non-additive and likely involve complex gene interactions. DiscussionOur study revealed subtle host family effects for the root fungal microbiome of P. radiata, with several heritable bacterial and fungal ASVs. This study broadens our understanding of host genetic influences on the composition of the root microbiome of P. radiata and indicates there are both opportunities and challenges for including microbiome-related traits in tree breeding programmes.
DOI: 10.3389/fpls.2026.17933742026-04-01
Yuanqiao Li, Yunni Wang, Wenfang Xu, Jinkai Tan
IntroductionTree intrinsic water use efficiency (iWUE) is an important metric for carbon and water balance in forest ecosystems. Tree iWUE has widely increased due to rising atmospheric CO2 and intensified drought. However, the dominant effects of rising atmospheric CO22, vapor pressure deficit (VPD), and soil moisture on iWUE are not fully understood.MethodsWe developed tree-ring width, stable carbon and oxygen isotopic chronologies derived from Chinese pine (Pinus tabulaeformis) stands across northern China to quantify the ecophysiological responses of iWUE to atmospheric CO2 and drought. ResultsiWUE was significantly correlated with atmospheric CO2 and VPD at both dry and wet sites. Furthermore, increased assimilation rate led to increased iWUE at both dry and wet sites. Notably, the beneficial effect of atmospheric CO2 on iWUE outweighed that of VPD in Chinese pine. DiscussionOur findings highlight the dominant role of rising atmospheric CO2 in enhancing assimilation rate and increasing iWUE of Chinese pine and will aid in defining the performance of this tree species under climate change in northern China.
DOI: 10.3389/fpls.2026.17210572026-04-01
Yu Chen, Yuyuan Chai, Xi Chen, Jing Shi
IntroductionThe rhizosphere metabolome is a crucial mediator of plant-substrate interactions, yet how different cultivation substrates reprogram this metabolic interface and influence crop performance remains poorly understood.MethodsUsing tomato as a model, we employed non-targeted metabolomics based on solvent extraction followed by gas chromatography-mass spectrometry (GC-MS) to compare rhizosphere metabolic profiles under three substrates: conventional facility soil (SL), pinecone residue (PR), and peat substrate (PS).ResultsWe identified and annotated 276 metabolites, with lipids and lipid-like molecules being the most abundant class (24.28%). Substrate type fundamentally reshaped the metabolome, with PR inducing the most distinct profile and PS triggering the most extensive metabolic reprogramming (277 differential metabolites). Notably, over 91% of differential metabolites were up-regulated upon tomato cultivation. The superior physicochemical properties (e.g., lower bulk density, higher nutrient availability) of organic substrates (PR and PS) were linked to both the distinct metabolic signatures and significant enhancements in tomato growth and fruit quality, particularly in PS which showed an 80.08% yield increase and a 50.19% boost in fruit vitamin C content.DiscussionOur findings demonstrate that organic substrates, especially peat, enhance plant performance by activating a more diverse and functionally specialized rhizosphere metabolome, providing a mechanistic basis for optimizing substrate selection in facility agriculture.
DOI: 10.3389/fpls.2026.17837192026-04-01
Dashuang Cao, Dongliang Guo, Chunyan Gu, Wanwan Fu, Xin Zhang, Wenhong Ma, Jiacong Li, Haixia Jiang, Huixin Zhao
The GhABA2 gene encodes a short-chain dehydrogenase/reductase involved in abscisic acid (ABA) biosynthesis and plays a crucial role in plant salt stress responses. To explore its function in cotton salt tolerance, we performed bioinformatic analysis, heterologous overexpression in Arabidopsis, and virus-induced gene silencing (VIGS) in cotton. Bioinformatic prediction revealed that the promoter region of the GhABA2 contains multiple cis-acting elements associated with ABA, light, and stress responses. Subcellular localization analysis indicated that GhABA2 was predominantly localized in the cytoplasm. Overexpression of GhABA2 in Arabidopsis significantly enhanced salt tolerance, as manifested by increased germination rates and root elongation. This was accompanied by a reinforced antioxidant system, with elevated activities of catalase (CAT), peroxidase (POD), glutathione reductase (GR), and ascorbate peroxidase (APX), alongside reduced accumulation of malondialdehyde (MDA) and H2O2. Furthermore, the transgenic lines exhibited higher relative water content (RWC), proline accumulation, and increased endogenous abscisic acid (ABA) levels under salt stress. Consistently, the expression of stress-responsive genes and ABA biosynthesis genes (AtNCED3, AtAAO3) was upregulated. Conversely, virus-induced gene silencing (VIGS) of GhABA2 in cotton compromised salt tolerance, characterized by diminished antioxidant enzyme activities (superoxide dismutase SOD, POD, GR, APX), reduced ABA content, and lower RWC and proline levels, but higher MDA and H2O2 accumulation. Correspondingly, the transcript levels of ROS-related genes and cotton ABA biosynthesis genes (GhNCED3a, GhNCED3c, GhAAO3) were downregulated. These findings demonstrate that GhABA2 positively regulates salt tolerance by modulating ABA biosynthesis and the antioxidant defense system. These findings elucidate the role of GhABA2 in modulating cotton salt stress responses and highlight its potential as a genetic target for breeding salt-tolerant cotton varieties.
DOI: 10.3389/fpls.2026.18032312026-04-01
Sunil Kumaraswamy, Yinghua Huang
Plant resistance to insects and diseases is a cornerstone of sustainable agriculture, reducing dependence on chemical pesticides and enhancing long-term crop resilience. Plant resistance is a suite of constitutive and inducible defenses, including structural barriers, biochemical defenses, signaling pathways activated upon recognition of pest or pathogen derived cues. Understanding how plants perceive biotic stress and mobilize these defenses through secondary metabolite production, reinforcement of physical barriers, and coordinated regulation of defense genes, is essential for designing effective management strategies Host plant resistance to insect herbivores exemplifies how specific plant traits can deter feeding, limit pest survival, or reduce reproduction. Advances in biotechnology, such as CRISPR/Cas9-based gene editing, RNA interference (RNAi), and transgenic approaches, have accelerated the development of crops with enhanced and durable resistance. These technologies enable precise manipulation of key resistance genes and pathways. Likewise, the integration of traditional methods with marker-assisted selection and genomic selection is improving the efficiency and accuracy of developing resistant cultivars. This review highlights the importance of dissecting plant-insect and plant-pathogen interactions at the molecular, biochemical, physiological levels to inform robust resistance integration. Future research that leverages advanced technologies and integrates resistance traits with agronomic performance will be pivotal for advancing sustainable pest management and ensure global food security. Together, these insights underscore the essential role of plant resistance in integrated pest management and crop improvement programs.
DOI: 10.3389/fpls.2026.1789793