Author: slquinlan

Carbohydr Polym. 2026 Sep 1;387:125464. doi: 10.1016/j.carbpol.2026.125464. Epub 2026 May 25.

ABSTRACT

Vascular plants require boron to cross-link the rhamnogalacturonan-II (RG-II) domain of pectin to form functional cell walls. Boronic acids, which form reversible esters with cis-diols like borate, have been proposed to influence RG-II cross-linking, though the mechanism remains unclear. We used suspension-cultured rose cells adapted to grow without boron to investigate the effect of boronic acids on RG-II dimerization. When grown with phenylboronic acid (PBA) as the sole boron source, nearly all RG-II was crosslinked, whereas methylboronic acid (MBA) only partially restored cross-linking. In contrast, in vitro assays showed that homogeneous RG-II monomers did not dimerize with alkyl or aryl boronic acids unless supplemented with hydrogen peroxide (H₂O₂), which oxidatively converts boronic acids to boric acid. Real-time NMR spectroscopy and density functional theory calculations provided insight into the reaction mechanism and energetics of oxidation respectively. Together, our data show that exogenous boronic acids are a source of boric acid for plants, and that the deboronation reaction generates aryl or alkyl alcohol byproducts that can undergo further chemical modification in planta. The fate and potential roles of these byproducts in planta remain to be determined.

PMID:42285657 | DOI:10.1016/j.carbpol.2026.125464

Annu Rev Phytopathol. 2026 Jun 12. doi: 10.1146/annurev-phyto-121423-082016. Online ahead of print.

ABSTRACT

This review aims to fill a critical gap-phytosanitation methods for inert surfaces, such as farming equipment, containers, tools, and shoes, to mitigate plant pathogen establishment and expansion. Although a core component to food system security and ecosystem stability, especially for mitigating emerging pathogen impacts, this is one of the least studied disease management tools and often lacks robust science-based practices. We herein synthesize what is known about inert surface phytosanitation practices across diverse microbiological and plant pest systems and highlight opportunities for improving both phytosanitation practices and approaches used for phytosanitation science. Basic frameworks are first established for the types of plant pathogen propagules that are spread on surfaces and dispersal risks posed by key inert surface types. This is followed by a discussion of primary surface phytosanitation methods, including physical, chemical, and heat-based approaches. Case studies of nursery/greenhouse and farm equipment phytosanitation are used to demonstrate both systems-strategies for application of phytosanitation best management practices and methods for developing science-based practices using the hazard analysis for critical control points (HACCP) approach. Opportunities for growth discussed throughout include the use of pathogen-specific analyses and epidemiological modeling to improve phytosanitation science and engineering advancements to make phytosanitation practices more efficient. Taken together, it is hoped that this synthesis can both function as a resource for research/extension practitioners looking to develop and improve phytosanitation practices and provide impetus for innovation.

PMID:42285548 | DOI:10.1146/annurev-phyto-121423-082016

Plants (Basel). 2026 May 27;15(11):1646. doi: 10.3390/plants15111646.

ABSTRACT

Magnolia cavaleriei var. platypetala ‘Tanchun’ is a newly registered flower variety in China, known for its characteristic floral aroma that intensifies toward full bloom. However, the composition of the volatiles of this aromatic flower remains uncharacterized. Here, we compared the volatile organic compound composition of Tanchun through gas chromatography-mass spectrometry and comparative transcriptome sequencing analyses of the stamen (S), pistil (P), and petals (T) during flower development, i.e., the bud (S1), semi-opened (S2), and bloom (S3) stages. We present a first comprehensive profile of 1395 metabolites from Tanchun’s floral organs. Terpenoids (26.2%) constituted the largest chemical group, followed by esters (17.52%), nitrogen compounds (9.83%), hydrocarbons (8.11%), alcohols (7.97%), aldehydes (6.53%), and others. We found that volatile organic compound (VOC) accumulation was both spatiotemporal and stage-specific. The S1 and S2 transition was characterized by scent notes of green, herbal, and waxy aromas, while the S2 and S3 shift exhibited a richer profile of fruity, sweet, and creamy notes, primarily in petals. A comparative VOC and transcriptomic analysis revealed that petals activate pathways for structural expansion and precursor mobilization, stamens enhance lipid and terpenoid metabolism, and pistils maintain a conserved profile. Importantly, the S1 and S2 transition in petals establishes the biochemical foundation by activating acyl-CoA, phenylpropanoid, and terpenoid synthesis pathways, which enables the activation of the butanoate metabolism pathway at S3, leading to the production of ester-rich compounds that define the floral scent. The transition to full bloom involves a shift to energy-efficient volatile biosynthesis, supported by carbohydrate restructuring and phytohormonal regulation. Our results provide the first comprehensive volatilome and transcriptome resource for ‘Tanchun’, revealing a highly efficient, multi-stage strategy for floral fragrance biosynthesis. This work lays a molecular foundation for future horticultural improvement and biotechnological applications in the flavor and fragrance industries.

PMID:42280683 | DOI:10.3390/plants15111646

Am J Bot. 2026 Jun 10:e70214. doi: 10.1002/ajb2.70214. Online ahead of print.

ABSTRACT

PREMISE: Global climate change has altered the eco-evolutionary trajectories of plant species, leading to observed shifts in phenotypes, such as earlier flowering. However, disentangling the contributions of plasticity and adaptation to trait changes remains challenging. The resurrection approach is a powerful method to study genetic and plastic responses by contrasting ancestral and descendant lineages from the same populations under common conditions.

METHODS: We compiled a database of resurrection studies to examine plant evolutionary responses to global change using a meta-analysis (46 studies) and quantitative and qualitative review (61 studies). Studies varied widely in the number of focal populations and intervening years separating generations, yet most involved annual plant species in North America and Europe.

RESULTS: We found evidence for rapid, contemporary evolution in over half of the cases. Moreover, evolution was often adaptive. As hypothesized, annuals showed greater magnitudes of evolutionary change than perennials. Across studies, annual descendants evolved earlier phenology and more resource-acquisitive leaf traits relative to ancestors. Under drought stress, annual and perennial species both evolved earlier phenology. Furthermore, in response to drought, annuals evolved increased plasticity in phenological and physiological traits but reduced plasticity in leaf traits, whereas perennials showed no evidence for evolution in plasticity.

CONCLUSIONS: Our study reveals that rapid evolution is common but not ubiquitous and highlights the key role of drought escape in plant responses to a warming world. Our review also suggests promising avenues for future resurrection research.

PMID:42272039 | DOI:10.1002/ajb2.70214

bioRxiv [Preprint]. 2026 May 15:2026.05.13.724861. doi: 10.64898/2026.05.13.724861.

ABSTRACT

Plants produce specialized metabolites that function in plant defense and as attractants to pollinators and symbionts. One class of specialized metabolites are terpenoids that are synthesized from universal C₅ building blocks via activities including terpene synthases, cytochromes P450, and glycosyl transferases. Some terpenes are highly valued for their use as insect repellants, fragrances, antimicrobial compounds, low calorie sweeteners, flavors, and medicines. Low abundance in target tissues, present in complex mixtures, as well as challenging extraction logistics are barriers to economic sustainable production of these compounds from their native species. While heterologous expression of terpenoid biosynthetic genes is feasible, the potential derivation of the products into conjugates via endogenous cytochromes P450 and glycosyl transferases limits this approach. In this project, we used multiplex gene editing technologies to overcome these challenges by creating novel tomato chassis with altered terpenoid biosynthetic capacity in fruit. Excluding central metabolic genes to minimalize impacts on growth and development, we selected 23 known and potential terpene-related genes expressed specifically in the fruit for gene editing. Fruit production and metabolic profiles of three chassis lines with alterations in the major classes of fruit specialized metabolites indicate loss of these genes is tolerated for fruit production. These combinatorial knockouts also showed modulation of native carbon reallocation toward endogenous sinks beneficial for a biosynthetic chassis. Establishing metabolite-modified fruit chassis demonstrates efficient combinatorial editing of entire branches of plant specialized metabolism, facilitating engineering of heterologous terpenes of industrial interest in tomato fruit.

PMID:42182293 | PMC:PMC13192727 | DOI:10.64898/2026.05.13.724861

Sci Rep. 2026 Jun 7. doi: 10.1038/s41598-026-55629-z. Online ahead of print.

ABSTRACT

Analysis of gene sequences showing signatures of selection can provide insights into the evolution and domestication of an organism and can suggest ways to accelerate crop improvement. Using whole-genome resequencing and RNA-seq-derived SNP data from 69 diverse sorghum accessions, we characterized genetic variation and identified genes showing evidence of potentially important roles in sorghum domestication and adaptation. Sorghum genes showing evidence of recent selection based on fixation index (Fst) include Sb02g037735, a protease inhibitor functioning in seed storage; and Sb02g029450, with a double-stranded RNA binding motif. Ten genes showing evidence of selective sweeps include 4 ion transporters that all are located in likelihood intervals for QTLs related to drought resilience of sorghum. Of 15 genes containing 16 deleterious SNPs fixed for different alleles between domesticated and wild sorghums, significantly low Tajima’s D indicates recent selection in two apoptotic ATPase-containing NB-ARC domain genes, signaling proteins involved in disease resistance and regulation of cell death. A group of 22 genes show evidence of convergent selection in sorghum, maize and rice. Integration of selection signatures, large-effect mutations, gene functional annotations, and positional (QTL) information suggests a small number of strong candidate genes involved in sorghum domestication and adaptation, while also identifying a broader set of plausible candidates. Comparison of genes under selection in sorghum, rice, and maize supports both convergent and divergent selection patterns during cereal evolution and domestication.

PMID:42252316 | DOI:10.1038/s41598-026-55629-z

J Econ Entomol. 2026 Jun 2:toag151. doi: 10.1093/jee/toag151. Online ahead of print.

ABSTRACT

Bemisia tabaci (Gennadius) is an economically damaging invasive pest to global vegetable production. Current management strategies rely heavily on insecticides, but increasing levels of resistance raise sustainability concerns. Therefore, strengthening integrated pest management (IPM) programs requires enhancing biocontrol through improved predator-pest interactions. Despite the well-established relevance of functional response modulation by multiple environmental factors, limited research has explored how plant traits and prey life stages interact to influence the efficiency of generalist predators in vegetable systems. To address this gap, we evaluated the functional responses of 2 adult generalist predators, Hippodamia convergens (Guérin-Méneville) and Geocoris punctipes (Say), against 3 nymphal instars of B. tabaci (second, third, and fourth) on 2 vegetable crops: yellow summer squash (Cucurbita pepo L.) and green beans (Phaseolus vulgaris L.) at 6 prey densities (5, 15, 25, 50, 75, and 100) under laboratory conditions. Results showed that both predators successfully preyed on all nymphal instars. Overall, predation did not differ significantly between host plants but varied among nymphal instars and increased with prey density. Both predators exhibited a Type III (sigmoidal) response to second instars and a Type II (hyperbolic) response to third and fourth instars. Attack rate increased with prey stage, with H. convergens showing the highest attack rate on fourth instars. Our findings highlight the importance of prey life stage in determining predator efficiency and support the potential of H. convergens and G. punctipes as promising biocontrol agents of B. tabaci, contributing to the development of more effective IPM strategies for vegetable production systems.

PMID:42228042 | DOI:10.1093/jee/toag151

Sci Rep. 2026 May 27. doi: 10.1038/s41598-026-52840-w. Online ahead of print.

ABSTRACT

Controlled Environment Agriculture (CEA) enables the cultivation of high-value crops under controlled environmental conditions, requiring precise nutrient monitoring to optimize fertigation. Standard practices to monitor plant nutrient status include nutrient leaf analysis (NLA), the reference method, but it does not reflect real-time status. Plant sap analysis offers real-time nutrient diagnostics; however, there is no standardized protocol for sap extraction methods across crops and individual nutrients. The objective of this study was to evaluate and compare multiple sap extraction methods for their reliability, practicality, and cost-effectiveness in diagnosing plant nutrient status in key CEA crops. Five sap extraction methods: ammonium acetate (AA), dry freezing (DF), extraction with ethyl ether (EE), extraction with potassium chloride (KCl), and tissue crushing (TC) were tested against NLA for assessing macro- and micronutrients in tomato (Solanum lycopersicum), cucumber (Cucumis sativus), and lettuce (Lactuca sativa) grown under CEA. For nitrate (NO₃⁻), KCL method was used as a reference and compared with EE and TC. The results indicated correlations between sap extraction methods and NLA were weak to moderate and varied across crops and nutrient types. The strongest correlations were obtained in lettuce using TC, with very high values for K (r = 0.99), Mg (r = 0.86), and Ca (r = 0.68). Other methods often yielded weak or negative correlations (e.g., tomato Ca with AA: r = – 0.36; cucumber Mg with KCl: r = – 0.15; lettuce Zn with EE: r = – 0.50). Sap NO₃⁻ correlations were variable, ranging from weakly positive (cucumber EE vs. KCl: r = 0.26) to negative (tomato TC vs. KCl: r = – 0.38), underscoring the complexity of NO₃⁻ dynamics and their dependence on crop physiology and developmental stage. A cost analysis showed that TC was the most affordable option, although it only worked for certain crops. These results indicate that, whereas some sap methods of extraction can produce indicative evidence of plant nutrient status in certain crops, none can accurately serve as a direct substitute for NLA.

PMID:42203811 | DOI:10.1038/s41598-026-52840-w

Plant Physiol. 2026 May 22:kiag293. doi: 10.1093/plphys/kiag293. Online ahead of print.

ABSTRACT

Cytosolic ascorbate peroxidases (APXs) have been proposed to have bifunctional 4-coumarate 3-hydroxylase (C3H) activity, linking redox regulation to lignin biosynthesis in plants. Although this dual role has been shown in vitro, in vivo validation remains limited. Here, we used CRISPR/Cas9 gene editing to knock out cytosolic 4-coumarate 3-hydroxylase/ascorbate peroxidase (C3H/APX) genes in Brachypodium distachyon and poplar (Populus tremula × P. alba). In Brachypodium, BdC3H/APX1 catalyzed the ascorbate-dependent hydroxylation of 4-coumarate to caffeate in vitro. Loss of BdC3H/APX1 function led to reduced lignin content, altered monomer composition, elevated H2O2 levels, and impaired growth, while double monoallelic knockouts of BdC3H/APX1 combined with a biallelic BdC3H/APX2 mutation (Bdc3h/apx1&2) exhibited severe developmental defects. Exogenous caffeate and ferulate rescued the growth and lignin phenotype of the Bdc3h/apx1 knockout mutants, whereas catalase reduced H2O2 without restoring plant growth. Similarly, CRISPR/Cas9-mediated PtC3H/APX1 knockout in poplar resulted in stunted growth and altered lignin composition, while the double Ptc3h/apx1&2 mutants were unable to regenerate from tissue culture. These results provide in vivo evidence of C3H/APX bifunctionality, suggesting that perturbed lignin biosynthesis is the primary cause of the growth defects typically observed in C3H/APX-deficient plants.

PMID:42175571 | DOI:10.1093/plphys/kiag293

Phytopathology. 2026 May 22. doi: 10.1094/PHYTO-01-26-0028-R. Online ahead of print.

ABSTRACT

Glomerella leaf spot (GLS) and bitter rot, caused by Colletotrichum species, are two of the most economically damaging diseases of apple (Malus domestica) in the southeastern USA. However, the causal species and their resistance to fungicides have not been well established in Georgia. We surveyed nine orchards in the Georgia apple-growing region in 2023 to identify the Colletotrichum species responsible for these two diseases and to assess their resistance to QoI fungicides. A total of 252 isolates were identified to species, revealing that bitter rot was caused by C. chrysophilum, C. fioriniae, C. fructicola, and C. siamense, with frequencies varying by orchard. In contrast, GLS was dominated by C. fructicola (86%) and, in some orchards, by C. chrysophilum. Sequencing of the cytochrome b (cytb) gene showed that the G143A mutation, which confers complete QoI resistance, was present in all species, but was especially common in C. fructicola (96%) and C. siamense (63%). Several isolates were heteroplasmic for cytb intron variants as well as for G143A, which could only be detected using multiple, genotype-specific primer sets for each isolate, emphasizing that careful detection is required in future studies. Mycelium inhibition assays confirmed that G143A conferred resistance in vitro, as most G143A isolates (98.8%) were classified as resistant using a discriminatory dose of pyraclostrobin while most wild-type isolates (97.7%) remained sensitive. Overall, these findings indicate that QoI fungicides are unlikely to control GLS in Georgia and will be ineffective for bitter rot at many locations.

PMID:42171591 | DOI:10.1094/PHYTO-01-26-0028-R