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Summary: Greenbeards are selfish genetic elements that make their bearers behave either altruistically towards individuals bearing similar greenbeard copies or harmfully towards individuals bearing different copies. They were first proposed by W. D. Hamilton over 50 yr ago, to illustrate that kin selection may operate at the level of single genes. Examples of greenbeards have now been reported in a wide range of taxa, but they remain undocumented in plants. In this paper, we discuss the theoretical likelihood of greenbeard existence in plants. We then question why the greenbeard concept has never been applied to plants and speculate on how hypothetical greenbeards could affect plant–plant interactions. Finally, we point to different research directions to improve our knowledge of greenbeards in plants. [ABSTRACT FROM AUTHOR]

The global flora is thought to contain a large proportion of herbs, and understanding the general spatiotemporal processes that shaped the global distribution of these communities is one of the most difficult issues in biogeography., We explored patterns of world-wide biogeography in a species-rich herbaceous group, the paper daisy tribe Gnaphalieae (Asteraceae), based on the hitherto largest taxon sampling, a total of 835 terminal accessions representing 80% of the genera, and encompassing the global geographic range of the tribe, with nuclear internal transcribed spacer (ITS) and external transcribed spacer (ETS) sequences., Biogeographic analyses indicate that Gnaphalieae originated in southern Africa during the Oligocene, followed by repeated migrations into the rest of Africa and the Mediterranean region, with subsequent entries into other continents during various periods starting in the Miocene., Expansions in the late Miocene to Pliocene appear to have been the driving force that shaped the global distribution of the tribe as forests were progressively broken up by the mid-continent aridification and savannas and grasslands expanded into the interior of the major continents. This pattern of recent colonizations may explain the world-wide distribution of many other organisms in open ecosystems and it is highlighted here as an emerging pattern in the evolution of the global flora. [ABSTRACT FROM AUTHOR]

Antony N. Dodd is a plant scientist who is interested in chronobiology and circadian rhythms. He was inspired to study plant biology after attending lectures by Howard Griffiths, which showed how biochemical processes in plants could be studied over 24-hour cycles. Dodd pursued a career in research because he was fascinated by the control of daily cycles of Crassulacean acid metabolism in plants. He is motivated by the social element of science and the interactions with his research group and colleagues. Dodd provides advice for scientists, such as investing time to get things right, not only chasing big papers, and being collegial. He also discusses his favorite New Phytologist papers, which explore the use of chemical biology to study circadian rhythms in plants. Dodd mentions two favorite plant species, Agave americana and Aegagropila linnaei, and their significance in his research. [Extracted from the article]

• Concentrations of atmospheric CO2 and tropospheric ozone (O3) are rising concurrently in the atmosphere, with potentially antagonistic effects on forest net primary production (NPP) and implications for terrestrial carbon sequestration. • Using free-air CO2 enrichment (FACE) technology, we exposed north-temperate forest communities to concentrations of CO2 and O3 predicted for the year 2050 for the first 7 yr of stand development. Site-specific allometric equations were applied to annual nondestructive growth measurements to estimate above- and below-ground biomass and NPP for each year of the experiment. • Relative to the control, elevated CO2 increased total biomass 25, 45 and 60% in the aspen, aspen–birch and aspen–maple communities, respectively. Tropospheric O3 caused 23, 13 and 14% reductions in total biomass relative to the control in the respective communities. Combined fumigation resulted in total biomass response of −7.8, +8.4 and +24.3% relative to the control in the aspen, aspen–birch and aspen–sugar maple communities, respectively. • These results indicate that exposure to even moderate levels of O3 significantly reduce the capacity of NPP to respond to elevated CO2 in some forests. [ABSTRACT FROM AUTHOR]

This article is a Commentary on the Virtual Issue 'Methane emissions from tree stems – current knowledge and challenges' that includes the following papers: Barba et al. (2019), Bréchet et al. (2021), Covey & Megonigal (2019), Feng et al. (2022), Flanagan et al. (2021), Jeffrey et al. (2019, 2021, 2023), Kohl et al. (2019), Machacova et al. (2021a,b, 2023), Megonigal et al. (2020), Pangala et al. (2013, 2014), Pitz & Megonigal (2017), Plain et al. (2019), Putkinen et al. (2021), Sjögersten et al. (2020), Takahashi et al. (2022), Tenhovirta et al. (2022), Wang et al. (2016), and Yip et al. (2018). Access the Virtual Issue at www.newphytologist.com/virtualissues. [ABSTRACT FROM AUTHOR]

Summary: Light intensity and quality influence photosynthesis directly but also have an indirect effect by increasing stomatal apertures and enhancing gas exchange. Consequently, in areas such as the upper canopy, a high water demand for transpiration and temperature regulation is created. This paper explores how light intensity and the natural high Blue‐Light (BL) : Red‐Light (RL) ratio in these areas, is important for controlling leaf hydraulic conductance (Kleaf) by BL signal transduction, increasing water permeability in cells surrounding the vascular tissue, in supporting the enormous water demands. Conversely, shaded inner‐canopy areas receive less radiation, have lower water and cooling demands, and exhibit reduced Kleaf due to diminished intensity and BL induction. Intriguingly, shaded leaves display higher water‐use efficiency (compared with upper‐canopy) due to decreased transpiration and cooling requirements while the presence of RL supports photosynthesis. [ABSTRACT FROM AUTHOR]

Yoselin Benitez Alfonso, a professor in interdisciplinary plant sciences at the University of Leeds, shares her journey and passion for plant science. Growing up in Cuba, she developed a love for nature and later pursued a degree in chemistry in Spain. Despite not having a biology background, she taught herself plant biology and became interested in plasmodesmata research. She is motivated by her love for research, the success of her students, and the impact of her contributions to teaching and diversity. She considers her father and various mentors as role models and enjoys reading papers on plasmodesmata research and plant symbiosis. Her favorite plant is the olive tree due to its symbolism, climate resilience, and economic significance. Yoselin is also involved in the Black in Plant Science Network and has received recognition for her leadership and academic achievements. [Extracted from the article]

Silke Robatzek, a Heisenberg Professor at Ludwig-Maximilian-University in Munich, Germany, discusses her interest in plant science and her decision to pursue a career in research. She is motivated by her curiosity and a desire to contribute to society through discovering new knowledge. Robatzek also highlights the importance of mentors and role models in her career, and she mentions her favorite papers from the New Phytologist journal. She expresses her fascination with olive trees and their genetic diversity in terms of plant immunity. [Extracted from the article]

In the basic pure-culture technique, fungus for inoculum is grown on stiff absorbent paper card over Potato Dextrose Agar, then this paper is removed aseptically and laid, fungus-side down, Oil to a two-dimensional array of roots of seedlings grown axenically on filter paper over a mineral salts agar medium. With the high inoculum potential achieved by this technique, ectomycorrhizas have been formed within one week of inoculating Pisolithus tinctorius Coker & Couch or Paxillus involutus (Batsch. ex Fr.) Fr. on to Eucalyptus globulus Subsp. bicostata (Maid. et al.) Kirkp., and over 50%, of root apices were converted to ectomycorrhizas within two weeks. The paper-based inoculum has also been applied successfully to convert peripheral roots of seedlings grown in peat-moss within clay pots. [ABSTRACT FROM AUTHOR]

This article is an Editorial to the Virtual issue on 'Remote sensing' that includes the following papers Chavana‐Bryant et al. (2017), Coupel‐Ledru et al. (2022), Cushman & Machado (2020), Disney (2019), D'Odorico et al. (2020), Dong et al. (2022), Fischer et al. (2019), Gamon et al. (2023), Gu et al. (2019), Guillemot et al. (2020), Jucker (2021), Koh et al. (2022), Konings et al. (2019), Kothari et al. (2023), Martini et al. (2022), Richardson (2019), Santini et al. (2021), Schimel et al. (2019), Serbin et al. (2019), Smith et al. (2019, 2020), Still et al. (2021), Stovall et al. (2021), Wang et al. (2020), Wong et al. (2020), Wu et al. (2021), Wu et al. (2017), Wu et al. (2018), Wu et al. (2019), Xu et al. (2021), Yan et al. (2021). Access the Virtual Issue at www.newphytologist.com/virtualissues. [ABSTRACT FROM AUTHOR]

The article discusses a comment made by Bourke et al. regarding the method described in Chen et al.'s paper on mapping quantitative trait loci (QTL) in autotetraploids. Chen et al. argue that their comment is correct based on facts and statistical principles. They explain that the method used in Bourke et al.'s paper lacks an essential component, which is genetic linkage analysis between QTLs and surrounding markers for QTL mapping in an outbred autotetraploid segregating population. Chen et al. also address the terminology and methodology used by Bourke et al., pointing out inconsistencies and inaccuracies. They conclude that their own method enables QTL mapping in autotetraploid species under a novel tetrasomic inheritance model and is based on rigorous scientific and statistical principles. [Extracted from the article]

This document is an interview with Debora Gasperini, a researcher in plant science. Gasperini explains that her interest in research began at a young age, inspired by her love for the natural world and engaging science classes. She chose to study molecular biology and became fascinated with plants due to their unique communication and resilience. Gasperini is motivated by the thrill of discovery and problem-solving, and she considers scientists like Rita Levi-Montalcini and Katherine Esau as role models for their passion and perseverance. She also discusses her favorite papers from the journal New Phytologist, which covers a wide range of plant science topics. Gasperini appreciates the adaptability and enduring nature of plants, which continue to inspire her research. [Extracted from the article]

This document is an interview with Ari Sadanandom, a Professor of Plant Molecular Sciences at the University of Durham. Sadanandom discusses his interest in plant science, his decision to pursue a career in research, and his motivations as a scientist. He also mentions his role models and inspirations throughout his career. Additionally, Sadanandom highlights some of his favorite papers from the journal New Phytologist, focusing on topics such as plant immunity, root development, and protein modifications. Finally, he shares his favorite plant, the Mimosa plant, and provides information about his research on protein modifications and its implications for agriculture. [Extracted from the article]

Alison Smith, a Professor of Plant Biochemistry at the University of Cambridge, discusses her interest in plant science and her career in research. She explains that her fascination with the productivity of gardening as a child led her to study Biochemistry in university and eventually specialize in photosynthetic organisms. Smith finds motivation in working with students and postdocs, as well as in the endless fascination of scientific discoveries. She also mentions several mentors and colleagues who have influenced her, including notable women plant scientists. Smith appreciates the variety of topics covered in the journal New Phytologist and highlights some of her favorite papers. Finally, she shares her favorite plant, the rose, for its showiness, and her favorite photosynthetic organisms, microalgae, for their diversity and potential in biotechnology. [Extracted from the article]

Interspecific C transfer was studied in laboratory microcosms containing pairs of 6-month-old Betula papyrifera Marsh. and Pseudotsuga menziesii (Mirb.) Franco seedlings growing in individual, root-restrictive (28 μm pore size) pouches filled with field soil. Interspecific transfer was examined by reciprocal labelling of seedlings with 13CO2(gas) and 14CO2(gas). At the time of labelling, the root zones of ectomycorrhizal (EM) B. papyrifera and P. menziesii were interconnected by an extensive network of EM mycelium. Carbon transferred through EM connections was distinguished from that through soil pathways by comparing microcosms where interconnecting hyphae were left intact vs. those where they were severed immediately before labelling. Transfer was bidirectional, and represented 5% of total isotope uptake by both B. papyrifera and P. menziesii together. P. menziesii received on average 50% more 14C and 66% more 13C from paper birch than vice versa, however, differences between species were not statistically significant. Neither net nor bidirectional transfer differed between severing treatments, leaving in question the relative importance of EM hyphae versus soil transfer pathways. The tendency for P. menziesii to receive more isotope than B. papyrifera corresponded with a 10-fold greater net photosynthetic rate per seedling and two-fold greater foliar N concentration of B. papyrifera than P. menziesii. [ABSTRACT FROM AUTHOR]

As proposed at the Second International Symposium on Fructan, a paper for discussion has been prepared which suggests alternative schemes based on that by A. L. Waterhouse circulated at the Symposium. This scheme has itself been modified in collaboration with N. J. Chatterton and published together with a glossary of terms. This glossary, also slightly modified, is reproduced here. The principal alternative (and additional) proposals have been made by N. C. Carpita, C. J. Pollock and D. H. Lewis, and compiled and edited by the last of this trio. [ABSTRACT FROM AUTHOR]

Details a study which examined the accumulation of H2O2 within the leaf mesophyll of Populus tremuloides aspen genotypes and seedlings of paper birch Betula papyrifera. Gene expression of catalase; Effects of ozone and carbon dioxide on the structure of ozone-tolerant aspen; Correlation between aspen clones, elevated ozone, birch and peroxisomes levels.

Ornithogalum ovules are crassinucellate, and the nucellar epidermis forms a nucellar cap which is secretory. The nucellus accommodates archespore and megaspore mother cell expansion by a concurrent increase in its size. It accommodates functional megaspore and megagametophyte expansion by simultaneously undergoing growth and partial degeneration. Nucellar degeneration is centrifugal and appears to be an autolytic process rather than a result of mechanical pressure from the growing megagametophyte. Megagametophyte development is of the Polygonum type. Mitotic divisions of the functional megaspore and its daughter cells are characterized by a perinuclear distribution of organelles. Some starch is stored in the micropylar end of the nucellus, but the majority is stored in the chalazal end around the hypostase. A strand of cytoplasm extends between the egg apparatus and antipodals. The micropylar polar nucleus moves across the central cell's vacuole in this strand to reach its mate. Antipodals initially are vacuolate but later fill with dense cytoplasm and numerous starch grains. Preliminary evidence from light microscopic investigation indicates a thin layer of wall material surrounds the egg apparatus. However, around the chalazal end of the egg this layer may be disjointed islands of wall material rather than a continuous wall. Synergid cytoplasm contains an abundance of organelles and a large filiform apparatus (FA) projects into it. In addition to the FA, synergid walls have a knobbed in growth around their micropylar end. We propose that the antipodals and central cell function initially as storage cells for nutrient reserves and later as nurse cells for embryo and endosperm whereas the synergids function as secretory cells which produce an agent(s) which attracts pollen tubes and, via the filiform apparatus, as cells which receive the pollen tube. [ABSTRACT FROM AUTHOR]

The chalazal end of the egg projects beyond the synergids while the micropylar end is in contact with the nucellar epidermis. The egg nucleus and nucleolus are large and, along with most of the cytoplasm, are located chalazally while a large vacuole occupies the micropylar end. The egg cell wall is attenuated chalazally but, based on preliminary light microscope observations, it does appear to surround the entire cell in some cases. The synergids each have a large chalazal vacuole with the majority of their cytoplasm in the micropylar half of the cell. Nuclei and nucleoli are large and other organelles are numerous. Plastids and endoplasmic reticulum (ER) are more numerous chalazally while mitochondria appear to be evenly distributed. Filiform apparatus (FA) formation occurs late in synergid maturation. The FA is large, well developed, and is surrounded by a vacuolate zone. Various sized vesicles with fibrillar or flocculent contents occur within the FA. The FA stains for both protein and RNA in addition to carbohydrate which is the dominant component. The synergid walls have a knobbed ingrowth around the periphery of their micropylar end. Neither egg nor synergids store any metabolites. This information, coupled with overwhelming evidence from the literature reviewed, has led me to conclude all angiosperm synergids are active in synthesizing and, via the FA, in secreting a substance(s) which influences the final phases of pollen tube growth. Movement of materials into a megagametophyte via the FA seems unlikely, but if it does occur, it is probably an inconsistent feature and only of trivial consequence. [ABSTRACT FROM AUTHOR]

Archesporial cell differentiation begins when ovules are four or five cells long. One parietal cell separates the archespore and nucellar epidermis. The parietal cell divides once anticlinally and its daughter cells divide once or twice periclinally resulting in four or six parietal cells. Archespore cytoplasm contains numerous small vacuoles and numerous circular, rod-shaped bodies which stain for protein. RNA content is high. Archesporial cells increase two- or threefold in size and produce a megaspore mother cell which is circular in cross-section and elliptical in longisection. Vacuoles seem to shrink slightly during the archespore/megaspore mother cell transition. Meiosis produces four megaspores separated from each other and from the nucellus by walls which stain intensely with basic fuchsin but do not fluoresce with Aniline blue. The chalazalmost megaspore typically becomes the functional megaspore while the others degenerate. Carbohydrates accumulate in the functional megaspore during the meiotic/mitotic interphase, and by metaphase, organelles, including amyloplasts, are in a perinuclear arrangement. [ABSTRACT FROM AUTHOR]

Ornithogalum ovules are bitegmic: the inner is initiated first, but both attain maturity at the same time. Both integuments are derived from the epidermal layer of the nucellus and are covered by a cuticle. Inner integument cells define the micropyle and those which line it are secretory. An outer integument is present only on the distal (non-funicular) side of the ovule. Its proximal portion apparently is fused congenitally with the funiculus. A funiculus attaches the ovule (and seed) to placental tissue. Proliferation of cells at the base of the funiculus contributes to development of the obturator. Funicular curvature causes the ovules to assume an anatropous orientation. A procambial strand branches from a ventral vein of the carpels and differentiates acropetally in the funiculus. At ovule maturity, vascular tissue terminates in the chalaza a few cells removed from the hypostase. Terminal cells of the vascular bundle consist only of tracheary elements with annular thickenings. [ABSTRACT FROM AUTHOR]

Summary: Cellulose is an essential component of plant cell walls and an economically important source of food, paper, textiles, and biofuel. Despite its economic and biological significance, the regulation of cellulose biosynthesis is poorly understood. Phosphorylation and dephosphorylation of cellulose synthases (CESAs) were shown to impact the direction and velocity of cellulose synthase complexes (CSCs). However, the protein kinases that phosphorylate CESAs are largely unknown. We conducted research in Arabidopsis thaliana to reveal protein kinases that phosphorylate CESAs.In this study, we used yeast two‐hybrid, protein biochemistry, genetics, and live‐cell imaging to reveal the role of calcium‐dependent protein kinase32 (CPK32) in the regulation of cellulose biosynthesis in A. thaliana.We identified CPK32 using CESA3 as a bait in a yeast two‐hybrid assay. We showed that CPK32 phosphorylates CESA3 while it interacts with both CESA1 and CESA3. Overexpressing functionally defective CPK32 variant and phospho‐dead mutation of CESA3 led to decreased motility of CSCs and reduced crystalline cellulose content in etiolated seedlings. Deregulation of CPKs impacted the stability of CSCs.We uncovered a new function of CPKs that regulates cellulose biosynthesis and a novel mechanism by which phosphorylation regulates the stability of CSCs. [ABSTRACT FROM AUTHOR]

Summary: A surge of papers have reported low leaf vulnerability to xylem embolism during drought. Here, we focus on the less studied, and more sensitive, outside‐xylem leaf hydraulic responses to multiple internal and external conditions. Studies of 34 species have resolved substantial vulnerability to dehydration of the outside‐xylem pathways, and studies of leaf hydraulic responses to light also implicate dynamic outside‐xylem responses. Detailed experiments suggest these dynamic responses arise at least in part from strong control of radial water movement across the vein bundle sheath. While leaf xylem vulnerability may influence leaf and plant survival during extreme drought, outside‐xylem dynamic responses are important for the control and resilience of water transport and leaf water status for gas exchange and growth. [ABSTRACT FROM AUTHOR]

Summary: Seminal scientific papers positing that mycorrhizal fungal networks can distribute carbon (C) among plants have stimulated a popular narrative that overstory trees, or 'mother trees', support the growth of seedlings in this way. This narrative has far‐reaching implications for our understanding of forest ecology and has been controversial in the scientific community. We review the current understanding of ectomycorrhizal C metabolism and observations on forest regeneration that make the mother tree narrative debatable. We then re‐examine data and conclusions from publications that underlie the mother tree hypothesis. Isotopic labeling methods are uniquely suited for studying element fluxes through ecosystems, but the complexity of mycorrhizal symbiosis, low detection limits, and small carbon discrimination in biological processes can cause researchers to make important inferences based on miniscule shifts in isotopic abundance, which can be misleading. We conclude that evidence of a significant net C transfer via common mycorrhizal networks that benefits the recipients is still lacking. Furthermore, a role for fungi as a C pipeline between trees is difficult to reconcile with any adaptive advantages for the fungi. Finally, the hypothesis is neither supported by boreal forest regeneration patterns nor consistent with the understanding of physiological mechanisms controlling mycorrhizal symbiosis. [ABSTRACT FROM AUTHOR]

• Over the last decade, technological developments have made it possible to quickly and nondestructively assess, in situ, the chlorophyll (Chl) status of plants. We evaluated the performance of these optical methods, which are based on the absorbance or reflectance of certain wavelengths of light by intact leaves. • As our benchmark, we used standard extraction techniques to measure Chla, Chlb, and total Chl content of paper birch (Betula papyrifera) leaves. These values were compared with the nominal Chl index values obtained with two hand-held Chl absorbance meters and several reflectance indices correlated with foliar Chl. • The noninvasive optical methods all provided reliable estimates of relative leaf Chl. However, across the range of Chl contents studied (0.0004-0.0455 mg cm[sup -2]), some reflectance indices consistently out-performed the hand-held meters. Most importantly, the reflectance indices that performed best (Chl NDI = (R[sub 750] - R[sub 705])/ (R[sub 750] + R[sub 705]), RII =∫750 705 (RλR/[sub 705] - 1) dλ) were not those most commonly used in the literature. • We report equations to convert from index values to actual Chl content, but caution that differences in leaf structure may necessitate species-specific calibration equations. [ABSTRACT FROM AUTHOR]

Summary: The 'One Hundred Important Questions Facing Plant Science Research' project aimed to capture a global snapshot of the current issues and future questions facing plant science. This revisiting builds on the original 2011 paper. Over 600 questions were collected from anyone interested in plants, which were reduced to a final list of 100 by four teams of global panellists. There was remarkable consensus on the most important topics between the global subpanels. We present the top 100 most important questions facing plant science in 2022, ranging from how plants can contribute to tackling climate change, to plant‐defence priming and epigenome plasticity. We also provide explanations of why each question is important. We demonstrate how focussing on climate change, community and protecting plant life has become increasingly important for plant science over the past 11 years. This revisiting illustrates the collaborative and international need for long‐term funding of plant science research, alongside the broad community‐driven efforts to actively ameliorate and halt climate change, while adapting to its consequences. [ABSTRACT FROM AUTHOR]

Non-mycorrhizal Betula papyrifera Marsh. seedlings and seedlings infected with Lactarius rufus (Scop. ex Fr.) Fr. or Scleroderma flavidum, E. & E. were treated with nutrient solutions containing 85 μM Ni or no Ni for 21 weeks. Ni was concentrated in the roots, with the highest concentrations being in the roots of plants infected with S. flavidum; Ni concentrations in stems were lowest in these seedlings. In general, Ni reduced the concentration of P, Mg, Ca, and Fe in shoot tissues. The concentration of P was correlated with that of Ni in the stems and roots. High P concentrations in the roots of S. flavidum-infected seedlings could be correlated with potential Ni-binding sites, allowing the Ni to be detoxified. Although Ni treatment reduced chlorophyll concentrations in L. rufus- infected and uninfected seedlings, this did not appear to be related to differences in tolerance caused by the fungi. [ABSTRACT FROM AUTHOR]

The role of ectomycorrhizas in the metal tolerance of birch seedlings from Sudbury, Ontario was investigated. Betula papyrifera Marsh. is one of the few tree species able to survive in the copper- and nickel-polluted area near Sudbury. Two types of birch seedlings were tested; those inoculated with Laccaria proxima (Boud.) Pat., Lactarius hibbardae Peck, Lactarius rufus (Scop. ex Fr.) Fries, or Scleroderma fiavidum E. & E. isolates originating from the Sudbury area, and those which were not inoculated. Once the seedlings were infected, they were grown in sand culture containing 34 or 85 μM Ni, 32 or 63 μM Cu, or a control solution. At the low nickel concentration, the mycorrhizal plants, especially those infected with S. fiavidum, grew significantly better than did non-mycorrhizal plants. At the higher nickel concentration, S. fiaviduminfected seedlings weighed 86 % of controls without nickel, while the other seedlings weighed only 52 to 61% of control. The good growth of S. fiavidum-infected birch seedlings may have been due to retention of nickel in the mycorrhizas. These seedlings had the highest root nickel contents and the lowest stem nickel contents. At the high concentration of copper, growth of the mycorrhizal seedlings was significantly reduced compared with the non-mycorrhizal seedlings. This reduction in growth of infected seedlings did not relate to an increase in the uptake or translocation of copper. Under the low copper treatment, infection with mycorrhizal fungi did not affect seedling growth. The potential role of iron and phosphorus in affecting host metal tolerance was investigated. Changes in the tissue concentrations of these elements did not relate to the effect of the fungi on metal tolerance. [ABSTRACT FROM AUTHOR]

Summary: If trees minimize self‐shading, new foliage in shaded parts of the crown should remain minimal. However, many species have abundant foliage on short shoots inside their crown. In this paper, we test the hypothesis that short shoots allow trees to densify their foliage in self‐shaded parts of the crown thanks to reduced costs.Using 30 woody species in Mediterranean and tropical biomes, we estimated the contribution of short shoots to total plant foliage, calculated their costs relative to long shoots including wood cost and used 3D plant simulations calibrated with field measurements to quantify their light interception, self‐shading and yield.In species with short shoots, leaves on short shoots account for the majority of leaf area. The reduced cost of short stems enables the production of leaf area with 36% less biomass. Simulations show that although short shoots are more self‐shaded, they benefit the plant because they cost less. Lastly, the morphological properties of short shoots have major implications for whole plant architecture.Taken together, our results question the validity of only assessing leaf costs to understand leaf economics and call for more integrated observations at the crown scale to understand light capture strategies in woody plants. [ABSTRACT FROM AUTHOR]

Summary: Leaf phosphorus (P) comprises four major fractions: inorganic phosphate (Pi), nucleic acids, phospholipids, P‐containing metabolites and a residual fraction. In this review paper, we investigated whether allocation of P fractions varies among groups of terrestrial vascular plants, and is indicative of a species' strategy to use P efficiently. We found that as leaf total P concentration increases, the Pi fraction increases the most, without a plateau, while other fractions plateau. Variability of the concentrations of leaf P fractions is greatest among families > species(family) > regions > plant life forms. The percentage of total P allocated to nucleic acid‐P (20–35%) and lipid‐P (14–34%) varies less among families/species. High photosynthetic P‐use efficiency is associated with low concentrations of all P fractions, and preferential allocation of P to metabolite‐P and mesophyll cells. Sequential resorption of P from senescing leaves starts with Pi, followed by metabolite‐P, and then other organic P fractions. Allocation of P to leaf P fractions varies with season. Leaf phytate concentrations vary considerably among species, associated with variation in photosynthesis and defence. Plasticity of P allocation to its fractions is important for acclimation to low soil P availability, and species‐specific P allocation is needed for co‐occurrence with other species. [ABSTRACT FROM AUTHOR]

In addition to studies on central carbon and whole plant metabolism, with isotopes, investigations into lipid metabolism are also an important focus and greatly intrigue me. Carbon assimilation, carbon partitioning, central carbon metabolism, isotope labeling, lipid metabolism, metabolic flux analysis, spatiotemporal metabolism, emergent properties Therefore, it should not be too surprising that the papers I mention here emphasize dynamic central carbon or lipid metabolism or whole plant metabolism unveiled using isotopes, by some excellent scientists in the field. Keywords: carbon assimilation; carbon partitioning; central carbon metabolism; emergent properties; isotope labeling; lipid metabolism; metabolic flux analysis; spatiotemporal metabolism EN carbon assimilation carbon partitioning central carbon metabolism emergent properties isotope labeling lipid metabolism metabolic flux analysis spatiotemporal metabolism 710 713 4 01/09/23 20230201 NES 230201 What inspired your interest in plant science?. [Extracted from the article]

Summary: Leaf structure plays an important role in photosynthesis. However, the causal relationship and the quantitative importance of any single structural parameter to the overall photosynthetic performance of a leaf remains open to debate. In this paper, we report on a mechanistic model, eLeaf, which successfully captures rice leaf photosynthetic performance under varying environmental conditions of light and CO2.We developed a 3D reaction‐diffusion model for leaf photosynthesis parameterised using a range of imaging data and biochemical measurements from plants grown under ambient and elevated CO2 and then interrogated the model to quantify the importance of these elements.The model successfully captured leaf‐level photosynthetic performance in rice. Photosynthetic metabolism underpinned the majority of the increased carbon assimilation rate observed under elevated CO2 levels, with a range of structural elements making positive and negative contributions. Mesophyll porosity could be varied without any major outcome on photosynthetic performance, providing a theoretical underpinning for experimental data.eLeaf allows quantitative analysis of the influence of morphological and biochemical properties on leaf photosynthesis. The analysis highlights a degree of leaf structural plasticity with respect to photosynthesis of significance in the context of attempts to improve crop photosynthesis. [ABSTRACT FROM AUTHOR]

This article is an interview with Peter J. Franks, a plant scientist who specializes in plant physiology and plant-climate interactions. Franks discusses his interest in plant science, which was sparked by his experiences in rainforests and his fascination with the diverse uses of plants by indigenous tribes. He also explains his decision to pursue a career in research, driven by his curiosity and the desire to contribute to scientific knowledge. Franks mentions his role models in the field and highlights some recent papers in the journal New Phytologist that have made significant advancements in understanding stomatal control and signaling in plants. He also shares his favorite plant species, including the extinct Cooksonia and the living fossil Austrobaileya scandens. Overall, Franks' research aims to integrate geological, molecular, and physiological information to understand the co-evolution of Earth's climate and vegetation. [Extracted from the article]

Summary: Drought is intensifying globally with climate change, creating an urgency to understand ecosystem response to drought both during and after these events end to limit loss of ecosystem functioning. The literature is replete with studies of how ecosystems respond during drought, yet there are far fewer studies focused on ecosystem dynamics after drought ends. Furthermore, while the terms used to describe drought can be variable and inconsistent, so can those that describe ecosystem responses following drought. With this review, we sought to evaluate and create clear definitions of the terms that ecologists use to describe post‐drought responses. We found that legacy effects, resilience and recovery were used most commonly with respect to post‐drought ecosystem responses, but the definitions used to describe these terms were variable. Based on our review of the literature, we propose a framework for generalizing ecosystem responses after drought ends, which we refer to as 'the post‐drought period'. We suggest that future papers need to clearly describe characteristics of the imposed drought, and we encourage authors to use the term post‐drought period as a general term that encompasses responses after drought ends and use other terms as more specific descriptors of responses during the post‐drought period. [ABSTRACT FROM AUTHOR]

This document is a profile of Martina Legris, a postdoctoral researcher at the Center for Integrative Genomics at the University of Lausanne in Switzerland. Martina's interest in plant science was inspired by her upbringing in a family of veterinarians and farmers, as well as her experiences playing with plants and animals in nature. She decided to pursue a career in research after participating in scientific meetings and outreach activities, where she met inspiring scientists and learned about their research. Martina is motivated by her love for her work and the sense of duty to contribute to society. She considers her mentors and female colleagues with children to be role models, and she appreciates the opportunity to choose her research topics and the variety of tasks in her everyday life. Martina's research focuses on plant development in response to light and temperature signals from the environment. She has published papers on the convergence of light and temperature signaling pathways in plants and the regulation of meristem activity. Martina's favorite plant is Ceiba speciosa, a large tree native to South America, and she also has a fondness for Arabidopsis thaliana, a tiny plant that has allowed her to uncover exciting aspects of plant biology. [Extracted from the article]

Tessa joined New Phytologist as an Advisor in 2022.For more information on Tessa, visit https://www.danforthcenter.org/our-work/principal-investigators/tessa-burch-smith/ ORCID: Tessa Burch-Smith https://orcid.org/0000-0002-5994-4343 Why did you decide to pursue a career in research? One recent I New Phytologist i paper that I enjoyed was 'Structural and functional relationships between plasmodesmata and plant endoplasmic reticulum-plasma membrane contact sites consisting of three synaptotagmins' (Ishikawa I et al i ., 2020) from the Shimada group. Keywords: intercellular trafficking; microscopy; Nicotiana benthamiana; plant viruses; plasmodesmata EN intercellular trafficking microscopy Nicotiana benthamiana plant viruses plasmodesmata 2155 2157 3 08/22/22 20220915 NES 220915 What inspired your interest in plant science?. [Extracted from the article]

Summary: Methane (CH4) exchange in tree stems and canopies and the processes involved are among the least understood components of the global CH4 cycle. Recent studies have focused on quantifying tree stems as sources of CH4 and understanding abiotic CH4 emissions in plant canopies, with the role of microbial in situ CH4 formation receiving less attention. Moreover, despite initial reports revealing CH4 consumption, studies have not adequately evaluated the potential of microbial CH4 oxidation within trees. In this paper, we discuss the current level of understanding on these processes. Further, we demonstrate the potential of novel metagenomic tools in revealing the involvement of microbes in the CH4 exchange of plants, and particularly in boreal trees. We detected CH4‐producing methanogens and novel monooxygenases, potentially involved in CH4 consumption, in coniferous plants. In addition, our field flux measurements from Norway spruce (Picea abies) canopies demonstrate both net CH4 emissions and uptake, giving further evidence that both production and consumption are relevant to the net CH4 exchange. Our findings, together with the emerging diversity of novel CH4‐producing microbial groups, strongly suggest microbial analyses should be integrated in the studies aiming to reveal the processes and drivers behind plant CH4 exchange. [ABSTRACT FROM AUTHOR]

Summary: Allopolyploidisation merges evolutionarily distinct parental genomes (subgenomes) into a single nucleus. A frequent observation is that one subgenome is 'dominant' over the other subgenome, often being more highly expressed.Here, we 'replayed the evolutionary tape' with six isogenic resynthesised Brassica napus allopolyploid lines and investigated subgenome dominance patterns over the first 10 generations postpolyploidisation.We found that the same subgenome was consistently more dominantly expressed in all lines and generations and that >70% of biased gene pairs showed the same dominance patterns across all lines and an in silico hybrid of the parents. Gene network analyses indicated an enrichment for network interactions and several biological functions for the Brassica oleracea subgenome biased pairs, but no enrichment was identified for Brassica rapa subgenome biased pairs. Furthermore, DNA methylation differences between subgenomes mirrored the observed gene expression bias towards the dominant subgenome in all lines and generations. Many of these differences in gene expression and methylation were also found when comparing the progenitor genomes, suggesting that subgenome dominance is partly related to parental genome differences rather than just a byproduct of allopolyploidisation.These findings demonstrate that 'replaying the evolutionary tape' in an allopolyploid results in largely repeatable and predictable subgenome expression dominance patterns. [ABSTRACT FROM AUTHOR]

Summary: The circadian clock plays essential roles in diverse plant biological processes, such as flowering, phytohormone biosynthesis and abiotic stress responses. The manner in which circadian clock genes regulate drought stress responses in model plants has been well established, but comparatively little is known in crop species, such as soybean, a major global crop. This paper reports that the core clock components GmLHYs, the orthologues of CCA1/LHY in Arabidopsis, negatively control drought tolerance in soybean.The expressions of four GmLHYs were all induced by drought, and the quadruple mutants of GmLHYs demonstrated significantly improved drought tolerance. Transcriptome profiling suggested that the abscisic acid (ABA) signaling pathway is regulated by GmLHYs to respond to drought tolerance.Genetic dissections showed that two homologous pairs of LHY1a and LHY1b redundantly control the drought response. Functional characterization of LHY1a and LHY1b in Arabidopsis and soybean further supported the notion that GmLHYs can maintain cellular homeostasis through the ABA signaling pathway under drought stress.This study improves our understanding of the underlying molecular mechanisms on soybean drought tolerance. Furthermore, the two homologues of LHY1a and LHY1b provide alternative targets for genome editing to rapidly generate mutant alleles in elite soybean cultivars to enhance their drought tolerance. [ABSTRACT FROM AUTHOR]

Summary: The wild relatives of modern wheat represent an underutilized source of genetic and phenotypic diversity and are of interest in breeding owing to their wide adaptation to diverse environments. Leaf photosynthetic traits underpin the rate of production of biomass and yield and have not been systematically explored in the wheat relatives.This paper identifies and quantifies the phenotypic variation in photosynthetic, stomatal, and morphological traits in up to 88 wheat wild relative accessions across five genera. Both steady‐state measurements and dynamic responses to step changes in light intensity are assessed.A 2.3‐fold variation for flag leaf light and CO2‐saturated rates of photosynthesis Amax was observed. Many accessions showing higher and more variable Amax, maximum rates of carboxylation, electron transport, and Rubisco activity when compared with modern genotypes. Variation in dynamic traits was also significant; with distinct genus‐specific trends in rates of induction of nonphotochemical quenching and rate of stomatal opening.We conclude that utilization of wild relatives for improvement of photosynthesis is supported by the existence of a high degree of natural variation in key traits and should consider not only genus‐level properties but variation between individual accessions. [ABSTRACT FROM AUTHOR]

Summary: That arbuscular mycorrhizal (AM) fungi covary with plant communities is clear, and many papers report nonrandom associations between symbiotic partners. However, these studies do not test the causal relationship, or 'codependency', whereby the composition of one guild affects the composition of the other. Here we outline underlying requirements for codependency, compare important drivers for both plant and AM fungal communities, and assess how host preference – a pre‐requisite for codependency – changes across spatiotemporal scales and taxonomic resolution for both plants and AM fungi. We find few examples in the literature designed to test for codependency and those that do have been conducted within plots or mesocosms. Also, while plants and AM fungi respond similarly to coarse environmental filters, most variation remains unexplained, with host identity explaining less than 30% of the variation in AM fungal communities. These results combined question the likelihood of predictable co‐occurrence, and therefore evolution of codependency, between plant and AM fungal taxa across locations. We argue that codependency is most likely to occur in homogeneous environments where specific plant – AM fungal pairings have functional consequences for the symbiosis. We end by outlining critical aspects to consider moving forward. [ABSTRACT FROM AUTHOR]

Summary: Nitrogen (N2)‐fixing moss microbial communities play key roles in nitrogen cycling of boreal forests. Forest type and leaf litter inputs regulate moss abundance, but how they control moss microbiomes and N2‐fixation remains understudied. We examined the impacts of forest type and broadleaf litter on microbial community composition and N2‐fixation rates of Hylocomium splendens and Pleurozium schreberi.We conducted a moss transplant and leaf litter manipulation experiment at three sites with paired paper birch (Betula neoalaskana) and black spruce (Picea mariana) stands in Alaska. We characterized bacterial communities using marker gene sequencing, determined N2‐fixation rates using stable isotopes (15N2) and measured environmental covariates.Mosses native to and transplanted into spruce stands supported generally higher N2‐fixation and distinct microbial communities compared to similar treatments in birch stands. High leaf litter inputs shifted microbial community composition for both moss species and reduced N2‐fixation rates for H. splendens, which had the highest rates. N2‐fixation was positively associated with several bacterial taxa, including cyanobacteria.The moss microbiome and environmental conditions controlled N2‐fixation at the stand and transplant scales. Predicted shifts from spruce‐ to deciduous‐dominated stands will interact with the relative abundances of mosses supporting different microbiomes and N2‐fixation rates, which could affect stand‐level N inputs. [ABSTRACT FROM AUTHOR]

Soluble polysaccharides, of natural and synthetic origins, are immobilized by nylon, nitrocellulose, and polyvinylidene difluoride blotting membranes. Retention of an acid and a neutral polysaccharide, measured using radioactive pectin and xyloglucan-rich hemicellulose, exceeded 90% on some blotting membranes eluted in aqueous media. The two polysaccharides displayed different binding characteristics. Several polyanionic uronic acid polysaccharides, bound strongly to nylon 66 (Hybond N, Amersham) and to positively charge-modified or cationic nylon blotting membranes (Hybond N+, Amersham), but much less strongly to paper, nitrocellulose or polyvinylidene difluoride. Fragments of pectin, including Rhamnogalacturonan I and Rhamnogalacturonan II, and galacturonic acid oligosaccharides as small as the dimer also bind to nylon membranes, and can he detected using cationic dyes or by means of their radioactivity. Xyloglucan-rich hemicellulose in general binds more strongly than pectin to the same substrates. Of the substrates tested charge-modified nylon gave best retention of pectin, and paper gave best retention of xyloglucan during washes in water and solutions of salts, acids and bases. The influence of pH and solutions of mono, di- and tri-valent salts on the retention of some pectic polysaccharides by nylon was investigated. A large proportion, in excess of 70% of pectin applied to charge-modified nylon, remained tightly bound at all salt concentrations up to 2 M. Soluble acid polysaccharides immobilized on blotting membranes could be detected by staining with cationic dyes, such as ruthenium red, alcian blue 8GX, and coriphosphine O, providing facile detection and a simple means of characterizing the cytochemical specificity of their staining reactions. Immobilized neutral polysaccharides, which do not react with cationic dyes, could usually be detected by the periodate-Schiff reaction, or, if labelled with radionuclides, by autoradiography or scintillation counting. Soluble polysaccharides, like proteins and nucleic acids, may therefore be immobilized on blotting membranes for investigation with cytochemical, immunocytochemical, and other molecular probing and detection procedures. Quantitative binding data showed marked differences in the affinity of different polysaccharides for blotting substrates. Detailed characterization of the binding behaviour is therefore a prerequisite for optimization and rational application of polysaccharide blotting. [ABSTRACT FROM AUTHOR]

Summary: Sulfurtransferases (STRs) constitute a large and complex protein family characterized by the presence of a rhodanese domain and implicated in diverse molecular and signaling processes as sulfur carriers. Although sulfurtransferases are present in the three domains of life and share evolutionary relationships, a high variability exists at different levels including the protein length and active site sequence, the presence of an indispensable catalytic cysteine residue, the domain arrangement and the subcellular localization. Because only Arabidopsis thaliana sequences have been inventoried so far, this paper aims at providing a detailed classification and inventory of evolutionary features of this family in photosynthetic organisms using comparative genomics, focusing on the oak genome. Based on the expansion of STRs in higher photosynthetic organisms, we classified the STR family in nine clusters depending on their primary sequence and domain arrangement. We found that oak possesses at least one isoform in all defined clusters and that clusters IV, V and VI contain plant‐specific isoforms that are located mostly in chloroplasts. The novel classification proposed here provides the basis for functional genomics approaches in order to dissect the biochemical characteristics and physiological functions of individual STR representatives. See also the Editorial on this article by Plomion & Martin, 226: 943–946. [ABSTRACT FROM AUTHOR]

Summary: Wheat stem rust, caused by Puccinia graminis Pers. f. sp. tritici (Pgt), is a devastating fungal disease threatening global wheat production. The present paper reports the identification of stem rust resistance gene Sr60, a race‐specific gene from diploid wheat Triticum monococcum L. that encodes a protein with two putative kinase domains. This gene, designated as WHEAT TANDEM KINASE 2 (WTK2), confers intermediate levels of resistance to Pgt.WTK2 was identified by map‐based cloning and validated by transformation of a c.10‐kb genomic sequence including WTK2 into susceptible common wheat variety Fielder (Triticum aestivum L.).Transformation of Fielder with WTK2 was sufficient to confer Pgt resistance. Sr60 transcripts were transiently upregulated 1 d post‐inoculation with Pgt, but not in mock‐inoculated plants. The upregulation of Sr60 was associated with stable upregulation of several pathogenesis‐related genes.The Sr60‐resistant haplotype found in T. monococcum was not found in polyploid wheat, suggesting an opportunity to introduce a novel resistance gene. Sr60 was successfully introgressed into hexaploid wheat, and we developed a diagnostic molecular marker to accelerate its deployment and pyramiding with other resistance genes. The cloned Sr60 also can be a useful component of transgenic cassettes including other resistance genes with complementary resistance profiles. [ABSTRACT FROM AUTHOR]

Summary: Global ecology – the study of the interactions among the Earth's ecosystems, land, atmosphere and oceans – depends crucially on global observations: this paper focuses on space‐based observations of global terrestrial ecosystems. Early global ecology relied on an extrapolation of detailed site‐level observations, using models of increasing complexity. Modern global ecology has been enabled largely by vegetation indices (greenness) from operational space‐based imagery but current capabilities greatly expand scientific possibilities. New observations from spacecraft in orbit allowed an estimation of gross carbon fluxes, photosynthesis, biomass burning, evapotranspiration and biomass, to create virtual eddy covariance sites in the sky. Planned missions will reveal the dimensions of the diversity of life itself. These observations will improve our understanding of the global productivity and carbon storage, land use, carbon cycle−climate feedback, diversity−productivity relationships and enable improved climate forecasts. Advances in remote sensing challenge ecologists to relate information organised by biome and species to new data arrayed by pixels and develop theory to address previously unobserved scales. [ABSTRACT FROM AUTHOR]

Summary: Censuses of tropical forest plots reveal large variation in biomass and plant composition. This paper evaluates whether such variation can emerge solely from realistic variation in a set of commonly measured soil chemical and physical properties.Controlled simulations were performed using a mechanistic model that includes forest dynamics, microbe‐mediated biogeochemistry, and competition for nitrogen and phosphorus. Observations from 18 forest inventory plots in Guanacaste, Costa Rica were used to determine realistic variation in soil properties.In simulations of secondary succession, the across‐plot range in plant biomass reached 30% of the mean and was attributable primarily to nutrient limitation and secondarily to soil texture differences that affected water availability. The contributions of different plant functional types to total biomass varied widely across plots and depended on soil nutrient status. In Central America, soil‐induced variation in plant biomass increased with mean annual precipitation because of changes in nutrient limitation.In Central America, large variation in plant biomass and ecosystem composition arises mechanistically from realistic variation in soil properties. The degree of biomass and compositional variation is climate sensitive. In general, model predictions can be improved through better representation of soil nutrient processes, including their spatial variation. [ABSTRACT FROM AUTHOR]

Summary: Although primarily valued for their suitability for oceanographic applications and soil moisture estimation, microwave remote sensing observations are also sensitive to plant water content (Mw). Since Mw depends on both plant water status and biomass, these observations have the potential to be useful for a range of plant drought response studies. In this paper, we introduce the principles behind microwave remote sensing observations to illustrate how they are sensitive to plant water content and discuss the relationship between landscape‐scale Mw and common stand‐scale metrics, including plant‐scale relative water content, live fuel moisture content and leaf water potential. Lastly, we discuss how various sensor types can be leveraged for specific applications depending on the spatio‐temporal resolution needed. [ABSTRACT FROM AUTHOR]

Summary: In mammalians and yeast, the splicing factor U2AF65/Mud2p functions in precursor messenger RNA (pre‐mRNA) processing. Arabidopsis AtU2AF65b encodes a putative U2AF65 but its specific functions in plants are unknown. This paper examines the function of AtU2AF65b as a negative regulator of flowering time in Arabidopsis.We investigated the expression and function of AtU2AF65b in abscisic acid (ABA)‐regulated flowering as well as the transcript abundance and pre‐mRNA splicing of flowering‐related genes in the knock‐out mutants of AtU2AF65b.The atu2af65b mutants show early‐flowering phenotype under both long‐day and short‐day conditions. The transcript accumulation of the flowering repressor gene FLOWERING LOCUS C (FLC) is reduced in the shoot apex of atu2af65b, due to both increased intron retention and reduced transcription activation. Reduced transcription of FLC results, at least partially, from the abnormal splicing and reduced transcript abundance of ABSCISIC ACID‐INSENSITIVE 5 (ABI5), which encodes an activator of FLC in ABA‐regulated flowering signaling. Additionally, the expression of AtU2AF65b is promoted by ABA. Transition to flowering and splicing of FLC and ABI5 in the atu2af65b mutants are compromised during ABA‐induced flowering.ABA‐responsive AtU2AF65b functions in the pre‐mRNA splicing of FLC and ABI5 in shoot apex, whereby AtU2AF65b is involved in ABA‐mediated flowering transition in Arabidopsis. [ABSTRACT FROM AUTHOR]

Summary: Anatomically preserved fossils allow estimation of hydraulic parameters, potentially providing constraints on interpreting whole‐plant physiology. However, different organ systems have typically been considered in isolation – a problem given common mismatches of high and low conductance components coupled in the hydraulic path of the same plant. A recent paper addressed the issue of how to handle resistance mismatches in fossil plant hydraulics, focusing on Carboniferous medullosan seed plants and arborescent lycopsids. Among other problems, however, a fundamental error was made: the transpiration stream consists of resistances in series (where resistances are additive and the component with the largest resistance can dominate the behavior of the system), but emphasis was instead placed on the lowest resistance, effectively treating the system as resistances in parallel (where the component with the smallest resistance will dominate the behavior). Instead of possessing high assimilation capacities to match high specific stem conductances, it is argued here that individual high conductance components in these Paleozoic plants are nonetheless associated with low whole‐plant productivity, just as can be commonly seen in living plants. Resolution of how to handle these issues may have broad implications for the Earth system including geobiological feedbacks to rock weathering, atmospheric composition, and climate. [ABSTRACT FROM AUTHOR]