Brief Summary of Minutes of Annual Meeting

Brief Summary of Minutes of Annual Meeting

Scientific presentations were given by all presenters, including three prospective additional members to the Multistate Project (Won Yim; Xin Wang and Rachael Morgan-Kiss).  The presentations covered topics outlined in detail below in the annual accomplishments section of the report.

Business Meeting Summary

NC1200 administration. At the 2025 meeting we'll need to organize the next grant, due in 2026. We will also need another Academic Advisor in 2025.  It can be an agricultural experimental director.  Work for renewal to be initiated in 2026.

Membership. Vote to be held for new members.

NC1200 hosting of past and future meetings. Past meetings 2018 Missou, 2019 Washington, 2020 MSU, 2021 Reno, 2022 Nebraska, 2023 Purdue.  Future meetings: 2024 Danforth Center hosted by Ru Zhang and Doug Allen; 2025 MSU hosted by Berkeley Walker (potentially, pending a discussion) with a backup group at Washington hosted by Asaph Cousins & Helmut Kirchoff.  Discussion was that in the future timing must occur either before/after the DOE meeting.

Accomplishments

Activities in 2023 are summarized under the different objectives.

Objective 1. Identify Strategies to optimize the assembly and function of the photosynthetic membrane.

• The Okita lab (WA-AES) conducted further studies to establish a relationship between the plastidic phosphorylase (Pho1) and PsaC (as well as PsaD), the terminal electron acceptor-donor of photosystem I. Past studies have shown that bacterial expressed PsaC and His-tagged PsaC were insoluble after expression in E. coli, which hindered our subsequent study of protein-protein interactions.  We have now demonstrated that PsaC fused to mCherry and MBP exhibited high expression levels and solubility. Additionally, PsaD fused to HaloTag was well-expressed and successfully purified.

• The Okita lab (WA-AES) conducted further studies on L80, a negative regulatory 80 residue peptide that is absent in the human and yeast phosphorylase. To identify the proximate location of the negative regulatory sequences, transgenic rice lines harboring selective deletions of the L80 peptide sequences were generated and seeds from T1 plants collected.

• The Okita lab (WA-AES) applied multiplex CRISPR-Cas12a, which generated two transgenic rice plants carrying long deletions in the L80 region. However, sequence analysis revealed that both had 199-nucleotide deletions near the N-terminus of L80, indicating off-frame deletions occurred.

• The Okita lab (WA-AES) generated homozygous Pho1 catalytic mutant (Pho1^cat-) and Pho1 ∆L80 catalytic mutant (Pho1∆L80^cat-) rice lines. Preliminary results indicates that the Pho1^cat- and Pho1∆L80^cat- lines have lower normal seeds yields similar to the Pho1 knockdown BMF136  indicating that a enzymatically active enzyme is essential for normal starch production in developing seeds. Pho1∆L80^cat seedlings, however, had faster growth rates as measured at 14 days after germination (DAG) as Pho1∆L80 compared to wildtype and Pho1^cat- These preliminary results suggest that the negative regulatory elements impacting growth function is independent of Pho1 catalytic activity.

• The Okita lab (WA-AES) identify T2 homozygous lines of Pho1 L80 various deletions: L80∆N [∆1-41], L80∆C[∆42-80]; L80∆M [∆21-59]; and L80∆HT [∆ 1-20, ∆ 61-80]. Preliminary analysis shows that L80∆C has longer panicle length and larger seeds than the three other transgenic genotypes.  These preliminary observations suggest that the C terminal end of the of L80 region has a negative regulatory element in modulating starch synthesis and plant growth.

Objective 2. Identify strategies to modify biochemical and regulatory factors that impact the photosynthetic capture and photorespiratory release of CO₂.

• The Furze Lab (IN-ARS) used a comparative framework along with gas exchange measurements and microCT imaging to examine the drivers of photosynthetic capacity between evergreen and deciduous Quercus (oak) species.

• This year’s work in the Furze Lab (IN-ARS) showed that deciduous species had higher photosynthetic capacity than evergreen. Their higher photosynthetic capacity was also driven by leaf biochemical and anatomical characteristics. For the latter, deciduous leaves had more densely packed mesophyll, a greater portion of palisade than spongy mesophyll, and a larger mesophyll surface area.

• This year’s work in the Furze Lab (IN-ARS) work suggests that greater investment in leaf structures such as densely-packed palisade mesophyll facilitates higher photosynthetic capacity in deciduous species and helps compensate for their shorter growing season.

Objective 3. Identify strategies to manipulate photosynthate partitioning.

• The Giroux lab (MT-AES) analyzed spring wheat leaf starch levels from recombinant inbred lines (RILs) varying for leaf starch. Flag leaves were collected at 14 days after flowering (DAF) over two consecutive field seasons.  Quantitative trait loci (QTL) analysis of RILs identified a single marker (BobWhite_c5970_731) associated with 21-34% of variation for days to flowering, seed yield, leaf starch, and plant biomass in this spring wheat population.  In this population leaf starch had a strong negative correlation with flowering date and plant productivity (p-value ≤ 0.001).

• Efforts to stably over-express recombinant proteins in cyanobacteria and other photosynthetic systems are hindered due to cellular proteasome activity that efficiently degrades foreign proteins. Recent work from the Melis Lab (CA-AES) showed that a variety of exogenous genes from plants, bacteria, and humans can be successfully and stably over-expressed in cyanobacteria, as fusion constructs with the abundant β-subunit of phycocyanin (the cpcB gene product) in quantities up to 10-15% of the total cell protein.

• The Melis Lab (CA-AES) found CpcB*P fusion proteins P did not simply accumulate in a soluble free-floating form in the cell but, rather, they assembled as functional (α,β*P)₃CpcG1 heterohexameric light-harvesting phycocyanin antenna discs, where α is the CpcA α-subunit of phycocyanin, β*P is the CpcB*P fusion protein, the asterisk denoting fusion, and CpcG1 is the 28.9 kDa phycocyanin disc linker polypeptide.

• This year the Melis Lab (CA-AES) expanded on this project and showed that the CpcA α-subunit of phycocyanin and the CpcG1 28.9 kDa phycocyanin disc linker polypeptide can also successfully serve as leading sequences in functional heterohexameric (α*P,β)₃CpcG1 and (α,β)₃CpcG1*P fusion constructs that permit stable recombinant protein over-expression and accumulation.

• The Melis Lab (CA-AES) found these complexes were shown to form a modified functional phycocyanin light-harvesting antenna and to contribute to photosystem-II photochemistry in the cyanobacterial cells.
• The Melis Lab (CA-AES) showed that cyanobacterial cells need the assembled phycocyanin for light harvesting, photosynthesis, and survival and, therefore, may tolerate the presence of heterologous recombinant proteins, when the latter are in a fusion construct configuration with phycocyanin in a functional but modified phycobilisome, thus allowing their substantial and stable accumulation.

• This year the Allen lab (MO-ARS) performed studies on metabolism in moss photosynthesis and carbon and nitrogen metabolism to understand the effects of altered CO2 and nitrogen level on moss growth and productivity. The studies indicated changes in moss development as a result of the altered provisions.

• The Allen lab (MO-ARS) analyzed the acyl-acyl carrier proteins of mutants developed in the Benning lab (MI-AES) to better understand the lipid membrane metabolism of the chloroplast. Mutants in the lab were developed to detail aspects of chloroplast lipid production. The work, in support of the Benning lab (MI-AES), indicated changes in lipid composition and flux that describe the production of lipid molecular species.

• The Benning lab (MI-AES) examined soybeans with enhanced levels of malic enzyme that result in production of increased lipid levels in developing seeds. Enhanced malic enzyme in the mitochondria resulted in more significant changes to the free amino acid composition; whereas when extra malic enzyme activity was in the plastid resulted in increases in total lipid. Additionally, changes in fatty acid composition reflected the redistribution of reducing equivalents between organelles that impacts polyunsaturation of fatty acids.

• In the Allen lab (MO-ARS) transgenic tobacco were engineered to make more lipid in the leaf were studied for responsiveness to heat stress. Stomatal opening and closing was impacted by the presence of lipid droplets in guard cells and resulted in most decrease in crop productivity.

Objective 4. Develop strategies to overcome limitations to photosynthetic productivity caused by developmental and environmental factors.

• The Giroux lab (MT-AES) analyzed candidate genes associated with the BobWhite_c5979_731 SNP marker and determined that it is a perfect marker for the gene This is the D genome homeologue of Vrn-D3, which is an orthologue of FT in Arabidopsis. Direct sequencing of RIL parents for this gene identified a single base pair deletion in the coding region of Vrn-3D in one of the RIL parents.  Further analysis of individual RILs differing for these alleles observed that plants carrying the deletion flowered later, and were higher yielding under low, moderate, and high nitrogen fertilizer regimes, indicating that this candidate gene is likely responsible for observed differences in flowering, leaf starch, and yield in this population.

• The Giroux lab (MT-AES) has identified multiple QTLs for flowering date and early leaf starch in the GWAS panel for the first field season.

• In another project, the Giroux lab (MT-AES) is examining leaf starch and plant productivity in a genome wide association study (GWAS) mapping panel. This trial was planted in two consecutive field seasons and leaf starch collected just prior to heading and at 14 DAF.  The first year of starch extractions has been completed and the second is in process.  In this population, early starch is positively correlated with flowering date yet  (p-value ≤ 0.001) while starch at grain fill is negatively correlated to days to antheis (p-value ≤ 0.001).  Starch at both developmental stages were not significantly correlated to yield. 

• The Glowacka Lab (NE-AES) characterized physiology and growth of the three selected transgenic soybean lines with unregulated NPQ in the growth-chamber conditions. Both under control (field water capacity (FWC) of 90%) and drought (60% FWC) transgenics consumed ~15% less water than wild type. Furthermore, in the desiccation test transgenics’ leaves lose ~20% less water than corresponding wildtype. In control conditions, transgenics had significantly bigger total leaf area what led also to significantly higher fresh leaf area. A much stronger advantage of transgenic modification was seen under drought conditions where not only leaf area and fresh leaf biomass but also the total above ground dry biomass was significantly bigger.

• The Glowacka Lab (NE-AE) characterized photosynthetic performance of the three selected transgenic soybean lines with unregulated NPQ in the field. In two field trials performed under rain-fed conditions, transgenics had significantly lower stomatal conductance, and significantly higher intrinsic water use efficiency with limited effect on leaf carbon assimilation.

• The Glowacka Lab (NE-AE) measured growth and yield of the three selected transgenic soybean lines with unregulated NPQ in the field. In 2022 field trail, transgenics had significantly higher dry leaf biomass and significantly higher total weight of seeds and total number of pods.

• The Below lab (IL – AES) obtained accurate data of soil composition, plant growth, yield, and components on the second year of the multi-year fertilizer trial. The third-year trial using maize (Zea mays ) on the static plots were established, grown, and resulting grain production data was obtained.

• The Below lab (IL – AES) obtained initial grain yield data in soybean [Glycine max (L.) Merr.] in response to combining planting date and additional agronomic management.

• The Below lab (IL – AES) characterized the interactions of multiple agronomic management techniques on soil microbiota and yield of long – term continuous maize.

• The Li lab (MS-AES) has been working on abiotic stresses especially droughtand salinity on photosynthetic productivity of crop plants. We found that silicon application can improve soybean photosynthesis and water use efficiency under water limiting conditions.

• The Li lab (MS-AES) recently isolated a dehydration-stimulated peptides from the leaves of rice plants subjected to water deficit. This dehydration-stimulated peptide was also up-regulated by salt stress. This dehydration-stimulated peptide was identified by mass spectrometry-based de novo sequencing as a cleaved carboxyl-terminal peptide of histone H2B. The work showed that histone tail cleavage can be an important molecular response to abiotic stress.

• The McAdam lab (IN-AES) investigated the role of evaporative demand on the speed of stomatal opening in the light across land plant species, discovering that stomatal opening speed is a function of evaporative demand only in species which have stomata that have mechanical interactions with the epidermis.

• The McAdam lab (IN-AES) used continuous monitoring of leaf water status and transpiration we have found that an increase in the levels of abscisic acid in the leaf occur at the onset of stomatal closure during drought, which leads to a reduction in photosynthetic rate.

• The McAdam lab (IN-AES) have found that during a drought, an increase in the levels of ABA in the leaf triggers stomatal closure in Fagus sylvatica - this result resolves a long-standing debate about the mechanism of stomatal regulation in anisohydric species.

• The McAdam lab (IN-AES) have also found that an increase in ABA levels in the leaf can trigger leaf senescence at the end of the growing season, but that this process is not dependent on ABA.

• The Harper lab (NV-ARS) collaborated with Jian Hua (Cornell) to provide evidence in Arabidopsis that resting cytosolic Ca²⁺concentrations are regulated by the combined activities of calmodulin-stimulated Ca²⁺-pumps in the plasma membrane, vacuole, and endoplasmic reticulum.  Knockout (KO) mutants in these Ca²⁺-pumps result in salicylic acid (SA)-dependent autoimmunity, which can be suppressed by lowering external supplies of calcium.

• The Harper lab (NV-ARS) found that knockout (KO) mutants corresponding to vacuolar Ca²⁺-pumps aca4/11 plasma membrane pumps aca8/10 both show severe hypersensitivities to chilling and heat stress environments.

• The Harper lab (NV-ARS) created an Arabidopsis lipid flippase mutant harboring a quintuple KO (knockout) of ala8/9/10/11/12. This mutant is 2.2-fold smaller and displays salicylic acid (SA)-dependent autoimmunity, which can be suppressed by lowering external supplies of calcium.
• The Cushman lab (NV-AES) reported on the developmental dynamics of crassulacean acid metabolism (CAM) in the cactus pear ( ficus-indica) to assess the relative contribution of C₃ photosynthesis and CAM in this highly productive and water-use efficient plant species. Developing O. ficus-indica primary and daughter cladodes begin as respiring sink tissues that transition directly to performing CAM once net positive CO₂ fixation is observed.

• The Cushman lab (NV-AES) obtained accurate vegetative (and fruit) biomass production data for 14 different accessions of cactus pear ( ficus-indica and O. cochenillifera). This three-year study in the Central Valley of California resulted in the identification of a hybrid Opuntia spp. accession PARL 845, hybrid No. 46 (O. ficus-indica x O. lindheimerii), which showed the highest annual mean cladode fresh weight (152.8 Mg ha^-1 year^-1) and cladode dry weight (13.3 Mg ha^-1 year^-1) among all accessions tested.

• The Cushman lab (NV-AES) assessed the history, evolutionary, phylogenetic, and biogeographic diversity of tissue succulence in plants, the potential role of this important anatomical adaptive trait to improve the climate resiliency of plants, and the current prospects for engineering tissue succulence to improve salinity and drought tolerance in crops.

• The Cushman lab (NV-AES) contributed to investigations into 1) the impact of starch biosynthesis in the daytime closure of stomata in the obligate CAM species, Kalanchoe fedtschenkoi, 2) the several different genetic mechanisms responsible for the loss of anthocyanins in betalain-pigmented Caryophyllales species, and 3) the role of epidermal bladder cells as effective barriers against arthropod herbivores rather than contributing only to abiotic stress tolerance.

• The Cushman lab (NV-AES) continued their phenotypic characterization of Teff (Eragrostis tef), a C₄ tropical grass and explored the mechanisms of drought tolerance in this and other cereals within the Poaceae.

Outputs

See Publications, below.

Plans for Coming Year

Objective 2. Identify strategies to modify biochemical and regulatory factors that impact the photosynthetic capture and photorespiratory release of CO₂.

• The Okita laboratory (WA-AES) will continue studies to characterize the interaction of Pho1 with PsaC and PsaD. Bacterial strains harboring expression plasmids for these proteins have been constructed and currently evaluated for co-expression and protein assembly. Alternatively, pull-down studies will be conducted where immobilized recombinant proteins will be incubated with rice extracts and the captured proteins identified by immunoblotting.

• The Okita laboratory (WA-AES) will continue studies on the negative regulatory L80 peptide by evaluating the growth and photosynthetic properties of rice plants harboring various deletions of the L80 sequences. Similar studies will be conducted with the gene-edited maize plants.

Objective 3. Identify strategies to manipulate photosynthate partitioning.

• In the coming year, the Furze Lab (IN-ARS) will pursue new work related to Objective 3. Identify strategies to manipulate photosynthate partitioning. This work will characterize the seasonal dynamics of nonstructural carbohydrate reserves in ‘ōhi‘a trees and will then manipulate photosynthate partitioning to investigate the role of nonstructural carbohydrate storage and defense investment in ‘ōhi‘a tree resistance to a novel destructive fungal pathogen Rapid ʻŌhiʻa Death.

• Successful completion of this work in the Furze Lab (IN-ARS) will identify how a tree’s carbon reserves buffer against biotic stress and will inform the development of disease mitigation strategies for Rapid ʻŌhiʻa Death and the management and conservation of Hawaiʻi’s forests.

• The Giroux lab (MT-AES) prepared a manuscript summarizing results in the RIL population, in which Vrn-3D was identified as the likely candidate behind yield, flowering time, and leaf starch differences.

• The Giroux lab (MT-AES) will continue to verify Vrn-3D by selecting for HIFs varying for the two alleles in a modern spring wheat population.

• The Giroux lab (MT-AES) will continue work in the GWAS population. A second year of early and grain fill leaf starch will be analyzed.  GWAS will be carried out for all yield traits for two growing seasons, as well as for the combined average of both seasons. 

• Current work in the Allen lab (MO-ARS), includes completing a manuscript on the response to heat stress of tobacco lines that were engineered to produce high levels of lipids in leaves.

• In the Allen lab (MO-ARS), analysis of fluxes in pennycress photosynthetic pods will be performed using isotopic labeling and metabolic flux analysis.

• The Melis Lab (CA-AES) will apply this promising phycocyanin fusion constructs technology to overexpress “oral vaccine”-type proteins that can be used in agriculture and aquaculture to immunize livestock, poultry, and fish, e.g., salmon, in commercial fish farming operations.
• Successful commercial application of this method by the Melis lab (CA-AES) would alleviate the need to apply excessive amounts of antibiotics in the feed of livestock, poultry, and commercial fisheries, which antibiotics, inevitably, find their way in the human food chain.

Objective 4. Develop strategies to overcome limitations to photosynthetic productivity caused by developmental and environmental factors.

• The Glowacka Lab (NE-AES) will continue to characterize seed yield from the 2023 field-grown transgenic soybean with NPQ modification.

• The Glowacka Lab (NE-AES) will perform seeds quality analyses of seeds developed under drought conditions in the transgenic soybean with NPQ modification.

• The Glowacka Lab (NE-AES) will continue to generate homozygous lines for remaining soybean transgenic events with modified NPQ.

• The Glowacka Lab (NE-AES) will test the effectiveness of varied promoters in the modification of stoma behavior through NPQ in soybean.

• The Glowacka Lab (NE-AES) will continue to characterize soybean transgenics with modified NPQ for physiological phenotype under control and stress conditions.

• The Below lab (IL – AES) will establish and conduct the fourth year of the multi – year fertilization study. Soybean will be grown with a portion receiving the every-year fertilization treatment.

• The Below lab (IL – AES) will continue to investigate the potential of using agronomic management in combination with planting date to increase the photosynthetic output of yields of soybean.

• The Below lab (IL – AES) will perform a survey of trifoliate nutrient levels throughout the season, which influences growth and yield of soybean. 

• The Below lab (IL – AES)plans to investigate the use of cover crops and decomposition techniques to enhance nutrient availability for growing continuous maize.

• The Li Lab (MS-AES) will apply functional analysis of the dehydration-responsive peptide to elucidate their roles in drought adaptation in plants.

• The Li Lab (MS-AES) will generate overexpression lines of the histone H2B gene in rice and test abiotic stress profiles of gene-overexpressing lines.

• The Li Lab (MS-AES) will generate RNA interference (RNAi) lines for the histone H2B gene in rice and test abiotic stress profiles of RNAi lines.

• In the coming year, the McAdam lab (IN-ARS) will continue to investigate the control of stomata by plant hydraulics during drought across land plant species.

• The McAdam lab (IN-ARS) will also investigate the environmental regulation of stomatal speed across grasses.

• A key objective for the coming year in the McAdam lab (IN-ARS) is to investigate the evolution of ABA biosynthesis and the role of this in determining stomatal control across land plants.

• Test candidate genes for their ability to improve heat-stress tolerance in pollen.

• Determine how changes in resting cytosolic Ca²⁺concentrations change a plants response to the environment.  

• Investigate the role of lipid flippases in regulating heat-stress tolerance. 

• The Cushman lab (NV-AES) will continue its life cycle assessment (LCA) and life cycle costing (LCC) analyses related to biomass and bioenergy production from cactus pear ( ficus-indica) in arid and semi-arid climates. We will complete our molecular phylogenetic analysis of the genetic diversity of the national Opuntia spp. germplasm collection in collaboration with the National Arid Land Plant Genetic Resources Unit (USDA-ARS). We will also continue to investigate the causative agents of Opuntia stunting disease and the molecular basis of spine and glochid formation in Opuntia.

• The Cushman and Yim labs (NV-AES) will continue work on transcriptome and genome sequencing of two obligate CAM species: cochenillifera (diploid) and O. ficus-indica (octoploid).

• The Cushman lab (NV-AES) will continue its work on investigating the beneficial effects of engineering tissue succulence in soybean (Glycine max).

• The Cushman lab (NV-AES) will continue its work on installing and optimizing synthetic CAM in thaliana and Glycine max to improve biomass productivity, water-use efficience, and drought tolerance.

• The Cushman lab (NV-AES) will continue its characterization of the phenotypic diversity within the USDA-ARS germplasm collection of Teff (Eragrostis tef) and in collaboration with the Yim lab (NV-AES) continue the genome and transcriptome analysis of drought-tolerant accessions of tef.

Oiestad, A.J., N.K. Blake, B.J. Tillett, J.P. Cook, and M.J. Giroux. Wheat (Triticum aestivum L.) Leaf Starch During Grain Fill is Linked to Flowering Time and Plant Productivity. Crop Science, in review. December 2023.

Glowacka K, Kromdijk J, Salesse-Smith CE, Smith C, Driever SM, Long S. (2023). Is chloroplast size optimal for photosynthetic efficiency? New Phytologist 239: 2197-2211.  http://doi.org/10.1111/nph.19091

Sahay S, Grzybowski M, Schnable JC, Głowacka K.^. (2023) Genetic control of photoprotection and photosystem II operating efficiency in plants. New Phytologist 239: 1068-1082. https://doi.org/10.1111/nph.18980

Rodrigues de Queiroz A, Hines C, Brown J, Sahay S, Vijayan J, Stone JM, Bickford N, Wuellner M, Glowacka K, Buan NR Roston RL. (2023). The Effects of Exogenously Applied Antioxidants on Plant Growth and Resilience. Phytochemistry Reviews 22: 407-447.  https://doi: 10.1007/s11101-023-09862-3

Sahay S, Shrestha N, Moura Dias H, Mural RV, Grzybowski M, Schnable JC, Glowacka K. Comparative GWAS identifies a role for Mendel’s green pea gene in the nonphotochemical quenching kinetics of sorghum, maize, and arabidopsis. bioRxiv doi: 10.1101/2023.08.29.555201

Kosola KR, Eller MS, Dohleman FG, Olmedo-Pico L, Bernhard B, Winans E, Barten TJ, Brzostowski L, Murphy LR, Gu C, Ralston L, Hall M, Gillespie KM, Mack D, Below FE, Vyn TJ (2023) Short-stature and tall maize hybrids have a similar yield response to split-rate vs. pre-plant N applications, but differ in biomass and nitrogen partitioning. Field Crops Research 295:108880. https://doi.org/10.1016/j.fcr.2023.10880.

B Mohanasundaram, S Koley, DK ALLEN, S Pandey: “Interaction between sugar signaling and nitrogen assimilation controls moss growth in elevated CO2” New Phytologist online Nov (2023).

Y Xu, R Cook, S Kambhampati, S Morley, J Froehlich, DK ALLEN, C Benning: “Arabidopsis Acyl Carrier Protein 4 and Rhomboid Like 10 Act Independently in Chloroplast Phosphatidic Acid Assembly”  Plant Physiology 193(4):2661-2676 (2023).  

SA Morley, F Ma, M Alazem, C Frankfater, H Yi, T Burch-Smith, TE Clemente, V Veena, H Nguyen, DK ALLEN: “Expression of malic enzyme reveals subcellular carbon partitioning for storage reserve production in soybeans” New Phytologist 239:1834-1851 (2023).

Hidalgo Martinez D, Melis A (2023) Cyanobacterial phycobilisomes as a platform for the stable production of heterologous enzymes and other proteins. Metabolic Engineering 77:174-187 https://doi.org/10.1016/j.ymben.2023.04.002

Momayyezi,M, Prats, K, McElrone, A, Furze, M. (In review) Biochemical and anatomical

leaf characteristics of oak trees drive differences in photosynthetic capacity between leaf habits. New Phytologist.

Pichaco Garcia J, Manandhar A, McAdam SAM. 2024. Mechanical advantage makes stomatal opening speed a function of evaporative demand.  Plant Physiology 10.1093/plphys/kiae023.

Mercado-Reyes JA, Soares Pereira T, Manandhar A, Rimer I, McAdam SAM. 2024. Extreme drought can deactivate ABA biosynthesis in embolism resistant species. Plant, Cell and Environment 47: 497-510.

Binstock BR, Manandhar A, McAdam SAM. 2024. Characterizing the breakpoint of stomatal response to vapor pressure deficit in an angiosperm. Plant Physiology 194: 732-740.

Kane CN, McAdam SAM. 2023. Abscisic acid driven stomatal closure during drought in anisohydric Fagus sylvatica. Journal of Plant Hydraulics 9: 002.

McAdam SAM, Manandhar A, Kane CN, Mercado-Reyes JA. 2024. Passive stomatal closure under extreme drought in an angiosperm species. Journal of Experimental Botany 10.1093/jxb/erad510.

Li Z, Harper JF, Weigand C, Hua J. (2023) Resting cytosol Ca²⁺ level is maintained by calmodulin regulated Ca²⁺ pumps and affects environmental responses in Arabidopsis. Plant Physiology 191(4):2534-2550. doi: 10.1093/plphys/kiad047.

Robichaux KJ, Smith DK, Blea MN, Weigand C, Harper JF, Wallace IS. (2023) Disruption of pollen tube homogalacturonan synthesis relieves pollen tube penetration defects in the Arabidopsis O-FUCOSYLTRANSFERASE1 mutant. Plant Reprod. doi: 10.1007/s00497-023-00468-5. PMID: 37222783

Hurtado-Castano N, Atkins E, Barnes J, Boxall SF, Dever LV, Knerova J, Hartwell J, Cushman JC, Borland AM. (2023) The starch-deficient plastidic PHOSPHOGLUCOMUTASE mutant of the constitutive crassulacean acid metabolisms (CAM) species Kalanchoe fedtschenkoi impacts diel regulation and timing of stomatal CO₂ responsiveness. Annals of Botany. DOI: 10.1093/aob/mcad017.

Niechayev NA, Meyer JA, Cushman JC. (2023) Developmental dynamics of crassulacean acid metabolism (CAM) in Opuntia ficus-indica. Annals of Botany. DOI: 10.1093/aob/mcad070

Peréz-Lopéz AV, Lim SD, Cushman JC. (2023) Tissue succulence in plants: Carrying water for climate change. Journal of Plant Physiology. 289: 154081. DOI: 10.1016/j.jplph.2023.154081.

Pucker B, Walker-Hale N, Yim WC, Cushman JC, Crum A, Yang Y, Brockington S. (2023) Evolutionary blocks to anthocyanin accumulation and the loss of an anthocyanin carrier protein in betalain-pigmented Caryophylalles. New Phytologist. In press. DOI: 10.1111/nph.19341.

Moog MW, Yang X, Bendtsen AK, Dong L, Crocoll C, Imamura T, Mori M, Cushman JC, Kant M, Palmgren M. (2023). Epidermal bladder cells as an herbivore defense mechanism. Current Biology. 33: 4662-4673. DOI: 10.1016/j.cub.2023.09.063.

Sage RF, Edwards EJ, Heyduk K, Cushman JC. (2023) Crassulacean acid metabolism (CAM) at the crossroads: Special issue in the Annals of Botany to honor 50 years of CAM research by Klaus Winter. Annals of Botany. DOI: 10.1093/aob/mcad160.

Mengistu M, Cushman JC. (2023) The role of drought-induced proteins regulating drought tolerance in cereals. In: Developing drought resistant cereals. Burleigh-Dodds Scientific Publishing. In press. DOI:

Neupane D, Niechayev NA, Petrusa LM, Heinitz C, Cushman JC. (2023) Biomass production potential of 14 accessions of cactus pear (Opuntia spp.) as a food, feed, and biofuel crop for arid lands. Journal of Agronomy and Crop Science. Submitted. DOI: