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The size and shape of plant leaves change with growth, and an accurate description of leaf shape is crucial for describing plant morphogenesis and development. Bilateral symmetry, which has been widely observed but poorly examined, occurs in both dicot and monocot leaves, including all nominated bamboo species (approximately 1,300 species), of which at least 500 are found in China. Although there are apparent differences in leaf size among bamboo species due to genetic and environmental profiles, bamboo leaves have bilateral symmetry with parallel venation and appear similar across species. Here, we investigate whether the shape of bamboo leaves can be accurately described by a simplified Gielis equation, which consists of only two parameters (leaf length and shape) and produces a perfect bilateral shape. To test the applicability of this equation and the occurrence of bilateral symmetry, we first measured the leaf length of 42 bamboo species, examining >500 leaves per species. We then scanned 30 leaves per species that had approximately the same length as the median leaf length for that species. The leaf‐shape data from scanned profiles were fitted to the simplified Gielis equation. Results confirmed that the equation fits the leaf‐shape data extremely well, with the coefficients of determination being 0.995 on average. We further demonstrated the bilateral symmetry of bamboo leaves, with a clearly defined leaf‐shape parameter of all 42 bamboo species investigated ranging from 0.02 to 0.1. This results in a simple and reliable tool for precise determination of bamboo species, with applications in forestry, ecology, and taxonomy. A simplified Gielis model is used to describe bamboo leaf shapes. Leave shapes of 42 bamboo species exhibit a perfect bilateral symmetry.

Premise of research. By adjusting leaf angles to orient toward or away from the sun, solar tracking modifies direct light interception, which consequently modifies leaf temperature. Leaf temperature is also influenced by leaf shape, due to its effect on heat transfer across boundary layers. Two co-occurring, closely related geophytic species of Pelargonium that differ dramatically in leaf shape were observed to exhibit differences in diurnal leaf movements. We asked whether leaf movements were consistent with solar tracking, whether they differed between the two species, and whether leaf shape and movement interacted to influence leaf temperature. Methodology.  We measured solar tracking, leaf temperatures, stomatal conductance, and light interception across a diurnal time course in midwinter in the field at De Hoop Nature Reserve in South Africa. Pivotal results. Highly dissected leaves of P. triste moved to track the sun more closely than shallowly lobed leaves of P. lobatum. In contrast to predictions based on leaf energy budget calculations, average diurnal temperatures for both leaf shapes remained close to ambient, with the only significant deviation occurring early in the morning in P. triste. The best model predicting the extent of leaf temperature difference from ambient included leaf shape, leaf movement, and the proportion of the leaf surface receiving direct light, and, notably, the interaction between leaf shape and movement. Conclusions. Leaf three-dimensionality interacts with movement to dictate direct light absorption, and all are critical to fully understanding leaf thermal profiles of nonflat leaves under field conditions.

Leaf growth initiates in the peripheral region of the meristem at the apex of the stem, eventually forming flat structures. Leaves are pivotal organs in plants, serving as the primary sites for photosynthesis, respiration, and transpiration. Their development is intricately governed by complex regulatory networks. Leaf development encompasses five processes: the leaf primordium initiation, the leaf polarity establishment, leaf size expansion, shaping of leaf, and leaf senescence. The leaf primordia starts from the side of the growth cone at the apex of the stem. Under the precise regulation of a series of genes, the leaf primordia establishes adaxial-abaxial axes, proximal-distal axes and medio-lateral axes polarity, guides the primordia cells to divide and differentiate in a specific direction, and finally develops into leaves of a certain shape and size. Leaf senescence is a kind of programmed cell death that occurs in plants, and as it is the last stage of leaf development. Each of these processes is meticulously coordinated through the intricate interplay among transcriptional regulatory factors, microRNAs, and plant hormones. This review is dedicated to examining the regulatory influences of major regulatory factors and plant hormones on these five developmental aspects of leaves.

1. The phenotypic plasticity of vegetative traits is a characteristic feature of aquatic plants, promoting survival and growth in the heterogeneous environments typical of wetlands. Less is known about plastic responses of life-history and reproductive traits, particularly patterns of sex allocation. 2. We investigated the plasticity of vegetative and reproductive traits in Sagittaria latifolia, a clonal aquatic plant whose populations are either monoecious or dioecious. Plants of the two sexual systems exhibit divergent life-history characters associated with the disturbed vs. competitive habitats in which monoecious and dioecious populations occur, respectively. We evaluated the prediction that populations of the two sexual systems would have different patterns of phenotypic plasticity because of the contrasting habitats in which they occur. 3. We grew four clonal replicates of 10 genotypes from seven monoecious and five dioecious populations (total = 480 plants) in two fertilizer treatments under glasshouse conditions and measured components of life history, leaf and flower morphology, and sex allocation. 4. The two sexual systems displayed divergent patterns of plasticity for four life-history traits but only flowering time and ramet production showed the expected pattern of greater plasticity in monoecious populations, and the reverse was true for flower production. Fertilization had opposite effects in the two sexual systems for corm production (increased in monoecious populations) and time to flowering (delayed in dioecious populations). 5. Leaf size generally increased due to the addition of fertilizer; however, this increase was substantially greater in dioecious populations. Larger leaf size in dioecious populations was associated with more convex leaves and greater surface area, potentially increasing light capture in the shaded and more competitive habitats in which these populations occur. 6. We found significant plasticity for female sex allocation in monoecious populations, with more female flowers at higher nutrient levels. However, the majority of populations had a significant genetic component to variation in sex allocation and/or significant genotype x environment interactions. These patterns are consistent with monoecy representing a flexible reproductive strategy for regulating mating opportunities in heterogeneous habitats.

A 12‐year‐old female Shih‐tzu dog was presented with a 2‐month history of cutaneous non‐pruritic multiple ulcerated or crusted nodules of less than 1.5 cm in diameter on eyelids, lips, abdomen, groin, thighs and perianal region. Several diagnostic tests were performed, including fine needle aspiration and skin biopsy of the cutaneous nodules. Cytologic interpretation was round cell neoplasm with multilobated (clover‐leaf shaped) nuclei. Histopathology revealed round neoplastic cells with prominent anisocytosis and anisokaryosis, and numerous mitotic figures; however, the origin of the cells was not identified. Immunohistochemical evaluation indicated that these cells were positive for CD79a and MUM‐1, but negative for CD3, CD20 and Pax 5. The patient was treated with chemotherapy, and the skin condition improved. Despite good response to chemotherapy, the patient was euthanized due to poor general health. Cells with multilobated (clover‐leaf shaped) nuclei can be seen on round cell neoplasm, especially plasma cell tumors or cutaneous plasmacytosis on cytology. Immunohistochemical evaluation with CD79a, CD3, CD20, MUM‐1, Pax 5 is indicated to confirm the origin of the cells.

• Commercial tomato (Solanum lycopersicum) is one of the most widely grown vegetable crops worldwide. Heirloom tomatoes retain extensive genetic diversity and a considerable range of fruit quality and leaf morphological traits. • Here the role of leaf morphology was investigated for its impact on fruit quality. Heirloom cultivars were grown in field conditions, and BRIX by yield (BY) and other traits were measured over a 14-wk period. The complex relationships among these morphological and physiological traits were evaluated using partial least-squares path modeling, and a consensus model was developed. • Photosynthesis contributed strongly to vegetative biomass and sugar content of fruits but had a negative impact on yield. Conversely leaf shape, specifically rounder leaves, had a strong positive impact on both fruit sugar content and yield. Cultivars such as Stupice and Glacier, with very round leaves, had the highest performance in both fruit sugar and yield. Our model accurately predicted BY for two commercial cultivars using leaf shape data as input. • This study revealed the importance of leaf shape to fruit quality in tomato, with rounder leaves having significantly improved fruit quality. This correlation was maintained across a range of diverse genetic backgrounds and shows the importance of leaf morphology in tomato crop improvement.

Leaves are the plant’s solar panel and food factory, and leaf traits are always key issues to investigate in plant research. Traditional methods for leaf trait measurement are time-consuming. In this work, an engineering prototype has been established for high-throughput leaf scoring (HLS) of a large number of Oryza sativa accessions. The mean absolute per cent of errors in traditional measurements versus HLS were below 5% for leaf number, area, shape, and colour. Moreover, HLS can measure up to 30 leaves per minute. To demonstrate the usefulness of HLS in dissecting the genetic bases of leaf traits, a genome-wide association study (GWAS) was performed for 29 leaf traits related to leaf size, shape, and colour at three growth stages using HLS on a panel of 533 rice accessions. Nine associated loci contained known leaf-related genes, such as Nal1 for controlling the leaf width. In addition, a total of 73, 123, and 177 new loci were detected for traits associated with leaf size, colour, and shape, respectively. In summary, after evaluating the performance with a large number of rice accessions, the combination of GWAS and high-throughput leaf phenotyping (HLS) has proven a valuable strategy to identify the genetic loci controlling rice leaf traits.

[...]quantifying and understanding the relationships among the functional traits of leaves are critical to our understanding of terrestrial ecosystem dynamics, nutrient cycles, responses to current global climate change, and the evolutionary trajectories of foliage form and function. Different perspectives on the allometry of leaf scaling Leaf shape and size play important roles in photosynthetic efficiency of plants through the growing season, and this Research Topic includes four papers looking at fundamental leaf scaling relationships focusing on the effects of plant size, leaf shape, and leaf age that address whether there is disproportionality in mass and area scaling relationships, a phenomenon called “diminishing returns”.Ma et al.studied 60 trees of an alpine evergreen oak (Quercus pannosa) to test whether tree size affects leaf shape, size, and leaf dry mass per unit area, and to test whether the proportional relationship between leaf area and the product of leaf length and width is a valid metric for calculating the leaf area of the leaves of trees differing in size (Figure 1). [...]the petiole/lamina mass ratio depends on the characteristics of the petiole (which is either short and thick or long and thin). Fast-return species have high SLA and low LDMC, whereas slow-return species have the opposite combination of these traits (Wright et al., 2004). [...]efforts to characterize the variation in these traits over large scales are very useful to map the functional characteristics of vegetation.Wang et al.investigated the effects of climatic and soil factors on plant resource utilization strategies using data collected from 926 plots across 163 forests in China and confirm the presence of significant differences in SLA and LDMC among plant functional types.

In plants, asymmetric cell divisions result in distinct cell fates forming large and small daughter cells, adding to the cellular diversity in an organ. SCARECROW (SCR), a GRAS domain-containing transcription factor controls asymmetric periclinal cell divisions in flowering plants by governing radial patterning of ground tissue in roots and cell proliferation in leaves. Though SCR homologs are present across land plant lineages, the current understanding of their role in cellular patterning and leaf development is mostly limited to flowering plants. Our phylogenetic analysis identified three SCR homologs in moss Physcomitrium patens, amongst which PpSCR1 showed highest expression in gametophores and its promoter activity was prominent at the mid-vein and the flanking leaf blade cells pointing towards its role in leaf development. Notably, out of the three SCR homologs, only the ppscr1 knock-out lines developed slender leaves with four times narrower leaf blade and three times thicker mid-vein. Detailed histology studies revealed that slender leaf phenotype is either due to the loss of anticlinal cell divisions or failure of periclinal division suppression in the leaf blade. RNA-Seq analyses revealed that genes responsible for cell division and differentiation are expressed differentially in the mutant. PpSCR1 overexpression lines exhibited significantly wider leaf lamina, further reconfirming the role in leaf development. Together, our data suggests that PpSCR1 is involved in the leaf blade and mid-vein development of moss and that its role in the regulation of cell division and proliferation is ancient and conserved among flowering plants and mosses.Key messageThe GRAS domain containing protein PpSCR1 regulates asymmetric cell divisions and governs leaf blade and mid-vein development in moss Physcomitrium patens.

Leaf morphological traits vary along climate gradients, but it is currently unclear to what extent this results from acclimation rather than adaptation. Knowing so is important for predicting the functioning of long-lived organisms, such as trees, in a rapidly changing climate. We investigated the leaf morphological warming responses of 18 tropical tree species with early (ES) abd late (LS) successional strategies, planted at three sites along an elevation gradient from 2400 m a.s.l. (15.2 °C mean temperature) to 1300 m a.s.l. (20.6 °C mean temperature) in Rwanda. Leaf size expressed as leaf area (LA) and leaf mass per area (LMA) decreased, while leaf width-to-length ratio (W/L) increased with warming, but only for one third to half of the species. While LA decreased in ES species, but mostly not in LS species, changes in LMA and leaf W/L were common in both successional groups. ES species had lower LMA and higher LA and leaf W/L compared to LS species. Values of LMA and LA of juvenile trees in this study were mostly similar to corresponding data on four mature tree species in another elevation-gradient study in Rwanda, indicating that our results are applicable also to mature forest trees. We conclude that leaf morphological responses to warming differ greatly between both successional groups and individual species, with potential consequences for species competitiveness and community composition in a warmer climate.