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Leaf anatomical traits may reflect plants adaption to environmental changes and influence ecosystem functions, as they regulate light absorption and gas exchange to some extent. Here, we hypothesized that leaf anatomical traits were closely related to gross primary productivity (GPP) because photosynthesis commonly occurs in the chloroplasts of palisade and spongy tissues in leaf. Eight leaf anatomical traits were measured in 916 plant species inhabiting from tropical to cold‐temperate forests in eastern China: adaxial epidermis thickness (AD), abaxial epidermis thickness (AB), leaf thickness (LT), palisade tissue thickness (PT), and spongy tissue thickness (ST), palisade–spongy tissue ratio (PT/ST), palisade tissue–leaf thickness ratio (PT/LT), and spongy tissue–leaf thickness ratio (ST/LT). Leaf anatomical traits showed significant latitudinal patterns at species, plant functional group (PFG), and community levels (p < .05), and they differed between PFG and community. Temperature and precipitation were the main factors influencing AD, AB, PT/ST, and PT/LT, explaining 33–72% of the total variation at large scale. Furthermore, AB, LT, PT/ST, and PT/LT were significantly correlated with the aridity index. Our findings filled the data gap of plant anatomical traits at regional scales, and broadened current knowledge on the adaptation strategies of plant anatomical traits, which also provided new evidence for linkages of plant traits and functioning across natural communities. A plain language summary is available for this article. Plain Language Summary

Salt tolerance mechanism of an extreme halophyte Salvadora persica was assessed by analyzing growth, nutrient uptake, anatomical modifications and alterations in levels of some organic metabolites in seedlings imposed to various levels of salinity (0, 250, 500, and 750 mM NaCl) under hydroponic culture condition. After 21 days of salt treatment, plant height, leaf area, and shoot biomass decreased with increase in salinity whereas the leaf succulence increased significantly with increasing salinity in S. persica. The RWC% of leaf increased progressively in salt-treated seedlings as compared to control. Na(+) contents of leaf, stem and root increased in dose-dependent manner whereas there was no significant changes in K(+) content. There was significant alterations in leaf, stem, and root anatomy by salinity. The thickness of epidermis and spongy parenchyma of leaf increased in salt treated seedlings as compared to control, whereas palisade parenchyma decreased dramatically in extreme salinity (750 mM NaCl). There was a significant reduction in stomatal density and stomatal pore area of leaf with increasing salinity. Anatomical observations of stem showed that the epidermal cells diameter and thickness of cortex decreased by salinity whereas thickness of hypodermal layer, diameter of hypodermal cell, pith area and pith cell diameter increased by high salinity. The root anatomy showed an increase in epidermal thickness by salinity whereas diameters of epidermal cells and xylem vessels decreased. Total soluble sugar content remained unchanged at all levels of salinity whereas reducing sugar content increased by twofold at high salinity (750 mM NaCl). The starch content of leaf decreased progressively in NaCl treated seedlings as compared to control. Total free amino acid content did not change at low salinity (250 mM), whereas it increased significantly at higher salinity (500 and 750 mM NaCl). The proline content increased in NaCl treated seedlings as compared to control. There was no significant changes in polyphenols level of leaf at all levels of salinity. The results from the present study reveal that seedlings imposed with various levels of salinity experience physiological, biochemical and anatomical modifications in order to circumvent under extreme saline environment. The vital mechanisms of salt tolerance in S. persica are higher accumulation of organic metabolites, increase in leaf succulency, efficient Na(+) sequestration in the vacuole, K(+) retention in the photosynthetic tissue and increase in WUE by reducing stomatal density. Therefore, S. persica is a potential halophytic species to be cultivated in saline lands to eliminate excess salt and make it favorable for agriculture.

Proprioception is the sense that lets us perceive the location, movement and action of the body parts. The proprioceptive apparatus includes specialized sense organs (proprioceptors) which are embedded in the skeletal muscles. The eyeballs are moved by six pairs of eye muscles and binocular vision depends on fine‐tuned coordination of the optical axes of both eyes. Although experimental studies indicate that the brain has access to eye position information, both classical proprioceptors (muscle spindles and Golgi tendon organ) are absent in the extraocular muscles of most mammalian species. This paradox of monitoring extraocular muscle activity in the absence of typical proprioceptors seemed to be resolved when a particular nerve specialization (the palisade ending) was detected in the extraocular muscles of mammals. In fact, for decades there was consensus that palisade endings were sensory structures that provide eye position information. The sensory function was called into question when recent studies revealed the molecular phenotype and the origin of palisade endings. Today we are faced with the fact that palisade endings exhibit sensory as well as motor features. This review aims to evaluate the literature on extraocular muscle proprioceptors and palisade endings and to reconsider current knowledge of their structure and function. What is the topic of this review? This review aims to evaluate the literature on proprioceptors and particular nerve specializations (palisade endings) in mammalian extraocular muscles (EOMs) and to reconsider current knowledge of their structure and function. What advances does it highlight? Classical proprioceptors (muscle spindles and Golgi tendon organs) are absent in the EOMs of most mammals. Instead, palisade endings are present in most mammalian EOMs. For many years, palisade endings were considered to be sensory but recent studies show that they combine sensory and motor features. The functional significance of palisade endings is still debated.

Leaf species of the family Brassicaceae have been studied, diagnostic features have been identified. Omitted by various types of trichomes: stellate, dendroid stomata are randomly arranged, numerous, non-submerged, mostly anomatid hemiparacytic anisocytic.

Background Accurate cell cycle progression is essential for plant growth and development. UVI4 ( UV-B-insensitive 4 ) and its homologue OSD1 ( Omission of the Second Division ) function as negative regulators of the anaphase-promoting complex/cyclosome (APC/C) and are critical for cell cycle regulation in plants. In potato, UVI4 and OSD1 have a single homologue, StOSD1/UVI4 , and the role of one copy of this gene in cell cycle regulation is largely unknown. Results We showed that mutation of StOSD1/UVI4 in potato resulted in a shorter plant height and a variegated leaf phenotype characterized by mosaic areas with dark green and light green colours. The mutant plants presented altered chloroplast distribution and decreased fluorescence signal in palisade cells within the light-green sectors, accompanied by a significant reduction in total chlorophyll content. Transcriptome analysis revealed the downregulation of genes associated with chlorophyll biosynthesis in the mutant. Paraffin sectioning revealed increased cell volume in the light green regions. Ploidy analysis via 5S rDNA fluorescence in situ hybridization (FISH) demonstrated that the StOSD1/UVI4 mutation induced endomitosis in the palisade cells in the light green sectors. Further ploidy determination in leaf cells via 26S rDNA and 5S rDNA FISH revealed that the StOSD1/UVI4 mutation led to a replication pattern combining incomplete replication with endomitosis. These findings indicate that the StOSD1/UVI4 mutation impairs chloroplast distribution and function in potato and triggers endomitosis. Additionally, the number of nonglandular trichomes on the leaf epidermis decreased, and the second division at meiosis was skipped in the StOSD1/UVI4 mutant. Conclusion Our findings establish a novel link between endomitosis and chlorophyll accumulation in plants. Additionally, we reveal roles for StOSD1/UVI4 in plant morphology (influencing trichome density) and meiosis (ensuring the second division). Collectively, these findings underscore a new role for StOSD1/UVI4 in regulating mitosis, plant morphology, and leaf development in potato.

The impact of water-deficit (WD) stress on plant metabolism has been predominantly studied at the whole tissue level. However, plant tissues are made of several distinct cell types with unique and differentiated functions, which limits whole tissue ‘omics’-based studies to determine only an averaged molecular signature arising from multiple cell types. Advancements in spatial omics technologies provide an opportunity to understand the molecular mechanisms underlying plant responses to WD stress at distinct cell-type levels. Here, we studied the spatiotemporal metabolic responses of two poplar ( Populus tremula× P. alba ) leaf cell types -palisade and vascular cells- to WD stress using matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI). We identified unique WD stress-mediated metabolic shifts in each leaf cell type when exposed to early and prolonged WD stresses and recovery from stress. During water-limited conditions, flavonoids and phenolic metabolites were exclusively accumulated in leaf palisade cells. However, vascular cells mainly accumulated sugars and fatty acids during stress and recovery conditions, respectively, highlighting the functional divergence of leaf cell types in response to WD stress. By comparing our MALDI-MSI metabolic data with whole leaf tissue gas chromatography-mass spectrometry (GC-MS)-based metabolic profile, we identified only a few metabolites including monosaccharides, hexose phosphates, and palmitic acid that showed a similar accumulation trend at both cell-type and whole leaf tissue levels. Overall, this work highlights the potential of the MSI approach to complement the whole tissue-based metabolomics techniques and provides a novel spatiotemporal understanding of plant metabolic responses to WD stress. This will help engineer specific metabolic pathways at a cellular level in strategic perennial trees like poplars to help withstand future aberrations in environmental conditions and to increase bioenergy sustainability.

Chlorophyll a fluorescence induction kinetics (CFI) is an important tool that reflects the photosynthetic function of leaves, but it remains unclear whether it is affected by leaf structure. Therefore, in this study, the leaf structure and CFI curves of sunflower and sorghum seedlings were analyzed. Results revealed that there was a significant difference between the structures of palisade and spongy tissues in sunflower leaves. Their CFI curves, measured on both the adaxial and abaxial sides, also differed significantly. However, the differences in the leaf structures and CFI curves between both sides of sorghum leaves were not significant. Further analysis revealed that the differences in the CFI curves between the adaxial and abaxial sides of sunflower leaves almost disappeared due to reduced incident light scattering and refraction in the leaf tissues; more importantly, changes in the CFI curves of the abaxial side were greater than the adaxial side. Compared to leaves grown under full sunlight, weak light led to decreased differences in the CFI curves between the adaxial and abaxial sides of sunflower leaves; of these, changes in the CFI curves and palisade tissue structure on the adaxial side were more obvious than on the abaxial side. Therefore, it appears that large differences in sunflower leaf structures may affect the shape of CFI curves. These findings lay a foundation for enhancing our understanding of CFI from a new perspective.

Leaf traits can be used to elucidate vegetation functional responses to global climate change. Pigments, water and leaf mass per area are the most used traits. However, detailed anatomical traits such as leaf thickness, the thickness of palisade and spongy parenchyma are often neglected, although they affect leaf physiological function and optical properties. Our aim was to produce partial least squares regression (PLSR) models for estimating leaf traits using biconical reflectance factor (BCRF). We established that estimation of leaf anatomical properties differs when using BCRF obtained from the upper and lower surface of the leaf. PLSR explained that 90% of the variability was based on total chlorophyll content (R2 = 0.95), spongy parenchyma to leaf thickness ratio (R2 = 0.94), equivalent water thickness (R2 = 0.93) and leaf mass per area (R2 = 0.91) or leaf thickness (R2 = 0.90). We conclude that internal asymmetry in leaf structure affects significantly leaf optical properties and should not be neglected in radiative transfer modelling at the leaf level and when upscaling leaf properties to the canopy.

This study was designed to explore the micro-anatomical characteristics of leaf and petiole of two unstudied West African native monotypic genera - Anogeissus and Qusqualis in Combretaceae with a view to characterizing the taxa, providing useful research-based information for identification. The samples were prepared following standard procedures. The light microscopic study of the transverse sections of the leaves in A. leiocarpus revealed a thick upper and lower cuticle while the cuticle on both leaf surfaces in Q. indica remain thin. The midrib vascular bundle of the leaf in Q. indica is characterized by arc-shape and starch grains were observed in the parenchyma cells of the ground tissue. The uniseriate rows of lamina epidermis were oval, squared, rectangular or polygonal in Q. indica while it was rectangular or slightly oval in A. leiocarpus. Vascular bundle in the leaves and petioles of both taxa were collateral. Simple, slender and short unicellular non-glandular trichomes were also observed in the leaf and petiole micro-anatomy of both taxa. It was concluded that the micro-anatomical features of the leaves and petioles are important parameters of characterization, used in the identification of the studied taxa.

Grasses of the Urochloa genus have been widely used in crop-livestock integration systems or as cover crops in no-till systems such as in rotation with maize. Some species of Urochloa have mechanisms to reduce nitrification. However, the responses of microbial functions in crop-rotation systems with grasses and its consequence on soil N dynamics are not well-understood. In this study, the soil nitrification potential and the abundance of ammonifying microorganisms, total bacteria and total archaea (16S rRNA gene), nitrogen-fixing bacteria (NFB, nifH), ammonia-oxidizing bacteria (AOB, amoA) and archaea (AOA, amoA) were assessed in soil cultivated with ruzigrass (Urochloa ruziziensis), palisade grass (Urochloa brizantha) and Guinea grass (Panicum maximum). The abundance of ammonifying microorganisms was not affected by ruzigrass. Ruzigrass increased the soil nitrification potential compared with palisade and Guinea grass. Ruzigrass increased the abundance of N-fixing microorganisms at the middle and late growth stages. The abundances of nitrifying microorganisms and N-fixers in soil were positively correlated with the soil N–NH4+ content. Thus, biological nitrogen fixation might be an important input of N in systems of rotational production of maize with forage grasses. The abundance of microorganisms related to ammonification, nitrification and nitrogen fixing and ammonia-oxidizing archea was related to the development stage of the forage grass.