Leaf Characteristics Research Articles

Leaf morphological variation in Betula medwediewii Regel populations from Türkiye

Leaf variations of Betula medwediewii in Türkiye with respect to its distribution pattern were studied because this plant taxon is a Euxine element and a distinct relict species in Türkiye. In this context, the aim of this study is to investigate variations in leaf morphological characteristics within and among B. medwediewii populations in natural distribution areas in Türkiye. Thus, the morphological leaf characteristics of four populations of B. medwediewii growing at different elevations spanning from 1472 to 2065 m.a.s.l in two cities (Artvin and Rize) and four boroughs (Arhavi, Borçka, Murgul, and Çamlıhemşin) of Türkiye were analyzed. The four populations were selected based on their natural distribution and 1,200 leaf samples belonging to 40 individuals were measured with ImageJ. According to the results of correlation analysis, statistically significant relationships were determined among morphological leaf characteristics. Mean values for petiole length (1.16 cm), leaf width (5.11 cm), leaf length (7.96 cm), length of lamina (6.79 cm), leaf area (26.62 cm²), leaf vein angle (54.21°), and number of primary leaf veins (20.03) were determined in all populations. Because B. medwediewii contributes to biodiversity and can preserve the ecological stability of the Turkish forest area, its conservation is crucial.

A single nucleotide substitution in BnaC02.LBD6 promoter causes blade shape variation in Brassica napus

Leaf shape is a part of ideotype. Appropriate leaf rolling aids compact plant architecture. Oilseed is a crucial crop, but the genetic basis for leaf shape development in rapeseed (Brassica napus) is unclear, and no corresponding genetic improvement germplasm resources are available. We identified a dominant mutant, INSIDE-ROLLING LEAF1 (IRL1), in rapeseed with internal rolling of leaves due to abnormal mesophyll cell development. It had drooped siliques and a semi-dwarf stature, reducing of one to two effective branch numbers. Map-based cloning and complementary validation confirmed BnaC02G0201100ZS as causal gene IRL1. BnaC02G0201100ZS encodes LATERAL ORGAN BOUNDARIES DOMAIN6 (BnaC02.LBD6). Phenotypic variation of the irl1 mutant was due to an increase in BnaC02.LBD6 expression owing to a single nucleotide substitution at the DNA binding site in the promoter. Phenotype of plants overexpressing BnaC02.LBD6 was similar to that of the irl1 mutant. Haploid analysis showed a rare variation in BnaC02.LBD6 promoter, resulting in a unique phenotype in the irl1 mutant. Transcriptome analysis showed the differential expression of genes related to leaf adaxial–abaxial polarity development, secondary metabolic processes, and hormone signalling pathways. We provide novel insights into rapeseed: the genetic basis of variation in leaf characteristics and valuable genetic resources for plant architecture improvement.

Identification of Different Medicinal Plants / Raw materials through PCA Using Support Vector Machine and K-Means Clustering Algorithms

This research explores the identification of plants by analyzing their leaves, utilizing digital image processing techniques to examine shape, color, and texture features. Machine learning algorithms are then applied to classify the plants based on these characteristics. The study involves an examination of various image processing methods integrated with machine learning to differentiate between plant species using leaf features captured in images. Image processing serves as the primary approach for categorizing plants based on unique leaf characteristics or specific leaf regions, enabling subsequent identification through image analysis. The research specifically focuses on the identification and classification of plant species based on the analysis of different leaf parts. The paper presents an overview of classification methods applied in plant leaf identification, with Support Vector Machine (SVM) being the primary algorithm used for plant identification and classification. Experimental results demonstrate enhanced accuracy in plant species identification based on leaf features, offering a more efficient and time-saving approach to plant identification

Flower or leaf characteristics, coloured or black and white illustrations – what helps student teachers to identify plants?

ABSTRACT For a sound understanding of biological diversity, it is not only important to identify species and recall their names, but to be able to distinguish between organisms based on a range of characteristic traits. However, whether flower or leaf characteristics are more important in identifying plant species and whether colour illustrations in identification books are more helpful than black and white ones is largely unexplored. With the help of a mobile eye-tracking device and pictures from two plant identification books, this study aimed to contribute to filling this knowledge gap. Thirty student teachers, all undergraduates in biology, were shown two freshly picked wildflowers (Medicago sativa and Echium vulgare) and asked to select the corresponding illustration from each of four plants on an identification sheet, which was either in colour or in black and white. For both plants, the number of fixations, and positively correlated fixation duration, were significantly higher for the flower than the leaf part. Although flowers and leaves were fixated longer and more frequently in the black-and-white illustrations, correct identifications were more likely with the coloured identification sheets. The results indicate that colour illustrations and sorting by flower characteristics are particularly helpful in identification aids for undergraduate students.

Morphological characterization of Iris hymenospatha and Iris histrio populations in Iran: implications for conservation and breeding.

The native populations of Iris hymenospatha and Iris histrio, two endangered bulbous species within the large Iris genus in Iridaceae, are threatened with extinction due to mining and other industrial activities in their natural habitats in Central Asia, including Iran. These species not only have a significant economic impact on the global horticultural industry due to their versatility and attractive phenotypic traits, but also have significant ecological value that necessitates their conservation. In this study, we examined the morphological and functional diversity between individuals within these two species, which exhibit high tolerance to environmental stresses. Our study examined 10 populations of I. hymenospatha and two populations of I. histrio based on bulb, flower, and leaf characteristics throughout Iran. We recognized a gradation of five different leaf shapes among I. hymenospatha populations with significant differences between some populations, including "Arak-Khomain" and "Arak-Gerdo". The "Jaro", "Natanz-Karkas", "Ardestan-Taleghan", "Arak-Rahjerd", "Arak-Gerdo", "Ganjnameh", and "Abas-Abad" populations of I. hymenospatha displayed maximal values in leaf width, stem diameter under flower, crown diameter, flower number, leaf number, and bulb diameter. The I. histrio "Velian" population had a significantly larger flower size, a longer stem length, a larger style width, a longer flowering date, and a higher plant height compared to the "Ganjnameh" population of I. histrio. Such characteristics of both species make them remarkable ornamental plants. Our study also revealed that I. hymenospatha populations grow on different soils and elevations and have the ability to adapt to different growing conditions. Given the threats they face, conservation through horticultural selection and propagation offers a viable conservation strategy for both species. This approach not only preserves the genetic diversity of these species, but also enables their further contribution to the horticultural industry.

Tolerance Mitigates Gall Effects When Susceptible Plants Fail to Elicit Induced Defense.

Variations in plant genotypes and phenotypes are expressed in ways that lead to the development of defensive abilities against herbivory. Induced defenses are mechanisms that affect herbivore insect preferences and performance. We evaluated the performance of resistant and susceptible phenotypes of Bauhinia brevipes (Fabaceae) against attacks by the gall-inducing insect Schizomyia macrocapillata (Diptera). We hypothesized that there is a positive relationship between resistance to S. macrocapillata and host plant performance because resistance can have a high adaptive value. We evaluated plant architecture, nutritional leaf quality, leaf fluctuating asymmetry, and reproductive capacity between phenotypes. Plant performance was evaluated at three ontogenetic stages: seed, seedling, and juvenile. Overall, there were no differences in vegetative and reproductive performance or asymmetry between the resistant and susceptible mature plants. We found no relationship between leaf nutritional quality and resistance to S. macrocapillata. Plant performance was consistent across ontogeny for both phenotypes, except for five variables. Contrary to our expectations, the susceptible plants performed equally well or better than the resistant plants, suggesting that tolerance and overcompensation to herbivory in B. brevipes may be mediated by induced defense. Our study highlights the importance of multiple layers of plant defense against herbivory, where plant tolerance acts as a secondary barrier in plants susceptible to gall-inducing insects.

Maize leaf disease recognition based on improved MSRCR and OSCRNet

Accurate identification of maize pests and diseases plays a crucial role in the growth and yield of maize. The recognition method of maize leaf diseases based on deep learning is currently a research hotspot. In practical applications, it is difficult to ensure a high recognition accuracy due to the impact of environmental factors (such as light intensity, background noise) and insufficient training data. To address this challenge, this paper proposes a maize image recognition method based on image enhancement and OSCRNet. Firstly, a maize leaf image enhancement framework and algorithm based on improved MSRCR were designed to enhance the characteristics of the maize leaf in a complex environment and to solve the problems of high noise and blur of maize images. Subsequently, the OSCRNet maize leaf recognition network model was established, which uses octave convolution with characteristics to accelerate network training and reduce unnecessary redundant spatial information in maize leaf images. Additionally, a self-calibrated convolution with multi-scale features was employed to realize the interactions of different feature information in the maize leaf images, enhance feature extraction, and solve the problems of similarity of maize disease features and easy learning disorders. Concurrently, batch normalization was employed to prevent network overfitting and enhance the robustness of the model. The experimental results showed that the highest identification accuracy of the proposed method for rust, gray leaf disease, northern wilt disease, and healthy maize are 96.67%, 94.86%, 92.81%, and 95.63%, respectively. Our methods were beneficial in solving the problems of slow efficiency, low accuracy and insufficient training data, and also outperformed other comparison models. The proposed method demonstrates strong robustness for maize disease images collected in the natural environment, providing a reference for the intelligent diagnosis of other plant leaf diseases.

Enhancing Malayalam Palm Leaf Character Segmentation: An Improved Simplified Approach

Enhancing Malayalam Palm Leaf Character Segmentation: An Improved Simplified Approach

Studies on Leaf Characters in <I>Malachra capitata</I> L.

Studies made on different leaf characters in Malachra capitata showed that the leaf angle is negatively correlated with the length and width of leaves but positively correlated with the area of leaves. The leaf angles are differentiated into three forms according to the position of leaves on the stem.

Deep Learning Based Tomato Leaf Disease Detection for Smart Farming

Tomato cultivation has a major role in global agriculture, contributing to both food security and economic stability. Still, tomato plants are susceptive to various diseases, which can specially reduce yield and quality. Plant disease early detection and treatment depend more and more on automatic disease identification and categorization technologies. In this paper, we present a Deep Learning based approach for tomato leaf diseases classification using VGG16 Convolutional Neural Network architecture. The VGG16 model is well-known for its superior picture categorization ability, A data set is used to train the VGG16 that includes healthy tomato leaves and leaves that are contaminated with common diseases like Early Blight, Late Blight, Leaf Mold, and Bacterial Spot. The dataset used in training and assessment comprises a varied assortment of high-resolution images acquired from various sources, guaranteeing the resilience and adaptability of the suggested model. Our utilization of data augmentation methods aims to improve the model's capacity to address variations in leaf characteristics, such as alterations in lighting, background complexity, and leaf positioning. Through experimental findings, we have validated the efficacy of our approach in precisely categorizing tomato leaf diseases with remarkable recall rates and precision. Comparative evaluations against leading techniques highlight the superior classification performance and computational efficiency of the VGG16-based model.

Characterization of rice (Oryza sativa L.) landraces from Majuli and surrounding riverine ecologies in Assam: Assessment of morphogenetic variability and submergence tolerance

AbstractRice landraces from the fragile riverine ecosystems surrounding Majuli islands in Assam are pivotal for local livelihoods, as well as for their potential in developing flood tolerant varieties. We characterized 87 landraces from Majuli, Dhemaji, and North Lakhimpur districts in Assam by assessing 36 agro‐morphological traits, submergence tolerance, and microsatellite diversity. Multivariate analyses revealed that grain and leaf characteristics, plant height, and tillering are important traits differentiating the cultivar types. Sixty‐six SSR markers generated 271 alleles with an average of 4.1 alleles per marker with population structuring in two clusters having an allele frequency divergence of 0.124. The Bao or deep‐water landraces displayed the highest phenotypic and genetic diversity, with potential genetic links to the aus and wild species. Sali (winter rice) and bora (sticky rice) landraces were predominantly indica type. Nearly 47% of the germplasm exhibited tolerance to two‐week submergence at seedling stage. Surveying SUB1A and SNORKEL genes revealed the presence of SUB1A‐1 and SNORKEL genes in 64% and 57% of the tolerant accessions, respectively. This study highlights the untapped potential of rice landraces in a fragile ecological region, providing insights into their agronomical traits, submergence tolerance, and genetic diversity. The findings lay the foundation for improved germplasm management and developing flood‐resilient rice varieties, crucial for sustainable agriculture in riverine ecosystems.

Drivers of Adoption: Mechanical Harvesting in the Corporate Sector Tea Plantations in Sri Lanka

Tea industry experts emphasize that selective manual harvesting is the best way to maintain leaf quality while preserving tea plant health. However, tea plantations tend to adopt mechanical harvesting to overcome labour shortages and harvesting costs. But the adoption of mechanical harvesting is still low, prompting further investigations. The purpose of this study is to investigate tea plantation managers’ concerns about the factors influencing mechanical harvesting adoption based on a case study as the research strategy. The results demonstrated that the majority of determinants that emerged, as drivers are consistent with the latent constructs, defined in adoption theories. Key drivers are employees’ attitudes, facilitation, continuous monitoring, training of women and skill development through regular practice. The organizational factors that cannot be explained through adoption theories were isolated. The findings concluded that multi-dimensional factors have emerged as the driving force, which will be useful to anyone looking into the real application.

The effect of drought‐induced leaf traits onFicusleaf palatability is species specific

AbstractDrought has a significant impact on plant–insect interactions by altering plant survival, growth, leaf quality, and defense traits. Tropical plants are particularly vulnerable to water depression because of shallow root depth. In the context of climate change, drought events are expected to increase in frequency and intensity; however, their impact on tropical ecosystems remains poorly known. Insect herbivores represent the largest feeding guild of arthropods, and they devour four to five times more plant material than vertebrates do. Understanding how drought affects plant traits and leaf palatability in a keystone and ecologically diverse plant genus, such asFicus(Moraceae), is crucial for predicting how climate change might alter tropical plant–insect interactions. We examined the impact of drought intensity and duration on the leaf nutritional quality, defensive traits, and herbivory damage by caterpillars in three tropical and one MediterraneanFicusspecies in a greenhouse. We also conducted food choice trials with generalist caterpillars to evaluate the impact of drought on herbivores. Drought intensity and duration had no direct effect on leaf palatability across theFicusspecies. However, drought indirectly affected leaf palatability via drought‐induced leaf traits in a species‐specific manner. Drought intensity and duration decreased leaf water content, resulting in decreased leaf palatability inF. benjaminaandF. lyrata. Leaf defensive traits such as flavonoid concentration were affected by drought intensity and decreased leaf palatability inF. carica. Drought influenced the leaf traits ofF. elastica, but none of them affected leaf palatability. Overall, this study establishes the link between drought and insect feeding on plants via leaf traits. The species‐specific responses to drought highlight the significance of climate‐related plant life histories in relation to climate change, underscoring the need for further investigations.

Ecophysiological responses of Phragmites australis populations to a tidal flat gradient in the Yangtze River Estuary, China.

Phragmites australis is a prevalent species in the Chongming Dongtan wetland and is capable of thriving in various tidal flat environments, including high salinity habitats. P. australis population displays inconsistent ecological performances, highlighting the need to uncover their survival strategies and mechanisms in tidal flats with diverse soil salinities. Upon comparing functional traits of P. australis at multiple tidal flats (low, middle, and high) and their responses to soil physicochemical properties, this study aimed to clarify the salt-tolerant strategy of P. australis and the corresponding mechanisms. These results showed that leaf characteristics, such as specific leaf area and leaf dry matter content, demonstrated more robust stability to soil salinity than shoot height and dry weight. Furthermore, as salt stress intensified, the activities of superoxide dismutase (SOD), catalase (CAT) and peroxisome (POD) in P. australis leaves at low tidal flat exhibited an increased upward trend compared to those at other tidal flats. The molecular mechanism of salt tolerance in Phragmites australis across various habitats was investigated using transcriptome sequencing. Weighted correlation network analysis (WGCNA) combined with differentially expressed genes (DEGs) screened out 3 modules closely related to high salt tolerance and identified 105 core genes crucial for high salt tolerance. Further research was carried out on the few degraded populations at low tidal flat, and 25 core genes were identified by combining WGCNA and DEGs. A decrease in the activity of ferroptosis marker gonyautoxin-4 and an increase in the content of Fe3+ in the degenerated group were observed, indicating that ferroptosis might participate in degradation. Furthermore, correlation analysis indicated a possible regulatory network between salt tolerance and ferroptosis. In short, this study provided new insights into the salt tolerance mechanism of P. australis population along tidal flats.

Maximizing Zygopetalum maculatum orchid yield through calcium nutrition: Unveiling calcium content and dynamics across different plant parts at different growth stages of the orchid

This study explores the pivotal yet often overlooked role of calcium (Ca) in Zygopetalum maculatum orchid cultivation. Six different treatments, featuring graded doses of Ca (ranging from 0 to 100 mg Ca L−1 nutrient solution), were used to assess the impact of Ca on growth, development, and physiological responses of the orchids. Notably, the Ca untreated control treatment (Ca0) exhibited a rapid decline in potting media pH (became acidic in reaction with time), whereas under Ca100 treatment potting media pH declined slowly and remained near neutral. Dehydrogenase activity in the potting media significantly increased under Ca100 treatment. Significant improvements in vegetative growth parameters, like, bulb length, bulb width, and leaf characteristics, were evident under Ca100 treatment compared to the Ca0 treatment. The economic yield, measured by the number of flower spikes and various floral attributes (i.e. number of florets per spike, spike length, florets size), displayed a remarkable enhancement under Ca100 treatment. The Ca100 treatment produced 100 % more number of flower spikes as compared to Ca0 treatment. The number of new shoot initiation, and overall flower biomass also substantially increased under Ca100 treatment. Ca content analysis in different plant parts revealed presence of elevated Ca concentrations in leaves, back bulbs, new bulbs, and roots under Ca100 treatment. The Ca content in back bulbs and roots decreased after flowering phase of the orchid, but the Ca levels in leaves and new bulbs remained statistically similar during both pre and post-flowering phases.These findings underscore the positive influence of Ca application on Zygopetalum maculatum orchids for enhancing its vegetative growth and economic yield. The study contributes valuable insights into Ca dynamics in different plant parts of the orchid, and recommends a 100 mg L−1 Ca application at 7-day intervals for improving Zygopetalum maculatum cultivation practices.

Morphological Evaluation of Pear cvs. Santa Maria, Williams, and Deveci Grafted onto Clonal and Seedling Rootstocks

This research was conducted to determine the effects of quince clonal rootstocks [Quince BA29 (BA29) and Quince A (QA)], pear clonal rootstocks [FOX9, FOX11, OHxF333, OHxF87 and FAROLD40] and European pear seedling rootstocks on the morphological characteristics of 'Santa Maria', 'Williams', and 'Deveci' pear cultivars in Bafra (Samsun) ecological conditions in the research years of 2021 and 2022. Morphological characteristics, such as rootstock diameter (mm), trunk diameter (mm), trunk cross-sectional area (cm2), tree height (cm), crown dimensions (width, length, height and volume), leaf stalk length (cm), leaf stalk thickness (mm), leaf dimensions (width, length, area), annual shoot length (cm), node numbers and internode length (cm) were examined in the study. Results of the study revealed significant variation in the case of research years on most morphological attributes; generally, the values were higher in the research year 2022 than in 2021. It has been determined that the effect of rootstocks on all the morphological characteristics was significant except for leaf stalk thickness. The highest morphological values were obtained from OHxF333, FOX11, and FAROLD40 compared to the other rootstocks, and the lowest values were recorded in FOX9, OHxF87, and seedling rootstocks, respectively. Considering the cultivars' effect on the evaluated morphological traits, the highest leaf characteristics, and internode length in the annual shoots were acquired from the 'Santa Maria' cultivar, but all other attributes were higher in the 'Deveci' cultivar. The ' Williams ' cultivar recorded almost all the lowest morphological values. The highest trunk cross-sectional area was determined in the 'Deveci'/OHxF333 (38.63 cm2) and the lowest in the 'Williams'/FOX9 (4.95 cm2). The longest annual shoots were determined in the 'Deveci'/FOX11 (43.05 cm) and the shortest in the 'Williams'/Seedling (16.11 cm). The highest leaf area was observed from the 'Santa Maria'/BA29 (21.11 cm2) and 'Santa Maria'/FOX11 (20.95 cm2) combinations. According to the results of the research, it was determined that OHxF333 rootstock among the evaluated rootstocks performed morphologically better than the others. FOX9 and OHxF87 pear clone rootstocks showed very poor performance compared to other rootstocks.

Can Arbuscular Mycorrhizal Fungi Enhance Crop Productivity and Quality in Hydroponics? A Meta-Analysis

Finding environmentally friendly solutions for crop growth and productivity has been gaining more attention recently. This meta-analysis aims to understand the combined application of arbuscular mycorrhizal fungi (AMF) and hydroponic systems compared to AMF in conventional (soil) systems. The analysis of up-to-date studies revealed that the root colonization, calculated as the proportion of colonized root segments relative to the total root length, by AMF in conventional (soil-based) culture exceeded hydroponic (or soilless) culture systems by 16.8%. The mean root colonization by AMF was determined to be 52.3% in hydroponic systems and 61.1% in conventional systems. Within hydroponic systems, the root colonization ranged from 2% to 20% after 10 days of inoculation, and notably, it exceeded 50% after 30 to 65 days, depending on the growing substrate and species. Under hydroponics, AMF application had a higher (compared to none-inoculated) positive effect on crop biomass and yield than fruit and leaf quality (antioxidants, phenols, and sugars) as well as leaf nutrients. However, AMF do not always have the potential to improve crop growth, quality and productivity in hydroponics. Among the studies analyzed in this review, approximately 34% (no effect: 29%; negative: 5%) reported no discernible positive effect on biomass or yield, 37% (no effect: 16%; negative: 21%) on fruit or leaf quality, and 60% (no effect: 47%; negative: 13%) on nutrient levels within plant tissues. To improve the performance of AMF in hydroponic systems, the meta-analysis recommended maintaining phosphorus levels in the nutrient solution within the range of 0.15 to 15.5 mg L−1 as elevated levels (40–75 mg L−1) were found to significantly reduce AMF colonization. Additionally, it was observed that certain hydroponic techniques, such as the presence of air bubbles generated by air pumps in floating hydroponic systems (Deep Flow technique) and continuous circulation of the nutrient solution (Ebb and Flow systems), may create dynamic conditions that could potentially hinder the introduction of AMF spores into hydroponic systems and potentially compromise the integrity of the spores and hyphae.

Investigating biological performance, oviposition and diet preference of the twospotted spider mite feeding on various melon genotypes

The twospotted spider mite, Tetranychus urticae Koch, is one of the most dangerous pests for many crops worldwide, including the melon. Here, we raise the hypothesis that the resistance of melon genotypes to the spider mite is associated with the morphological characteristics of the leaves. We determined (i) the feeding preference and oviposition suitability of T. urticae on four melon genotypes, (ii) various biological parameters and population growth rate (ri) of T. urticae on different melon genotypes, (iii) the leaf morphology of the melon genotypes, and (iv) the relationship between the leaf characteristics and resistance to T. urticae. In no choice tests, lower numbers of adults and eggs of T. urticae were found in the genotypes CNPH 06–1047-343, CNPH 11–1071-43, and CNPH 06-1047-341 compared to control (Goldex). Individuals that fed on CNPH 06–1047-343, CNPH 06–1047-341, and CNPH 11–1071-43 genotypes had a longer egg incubation time, longer development time, lower immature viability, longer time to reach adult stage (egg–adult) and lower instantaneous rate of increase compared to control. These findings are in line with the fact that these three genotypes had thicker epidermis and greater mesophyll thickness than control genotype “Goldex”. Even the genotypes CNPH 06–1047-343, CNPH 06–1047-341, and CNPH 11–1071-43 had higher trichome densities, this morphological characteristic was not related with the resistance to T. urticae. CNPH 06–1047-343, CNPH 06–1047-341, and CNPH 11–1071-43 showed antibiosis and antixenosis against T. urticae and that resistance of the melon to T. urticae wss associated with the greater thickness of the leaf epidermis and mesophyll.

Plants in the caatinga possess multiple adaptative leaf morphoanatomical traits concurrently, a pattern revealed from a systematic review

Plants in seasonally dry forests, such as the Caatinga in Brazil, possess adaptive characteristics to endure prolonged periods of drought and intense sunlight. However, few studies have delved into understanding, as proposed here, the convergence of these traits based on morphoanatomical features. Therefore, based on a systematic review, we investigated the morphoanatomical traits of Caatinga plant's leaves in terms of their occurrence and frequency among species, as well as their combinations. This review encompasses data from 69 species distributed across 24 botanical families, with 13 species exclusive to the Caatinga. Through this review, we present the most common morphoanatomical leaf traits of Caatinga plants, discussing their functional significance in dry forests. Traits such as uniseriate epidermis, tector trichomes, amphistomatia, dorsiventral mesophyll and crystals were the most prevalent. Additionally, traits not typically described as advantageous for semi-arid regions, such as stomata at the same level and/or above common epidermal cells, were identified. Our review unveils the significant sharing of morphoanatomical leaf characteristics among Caatinga plants, with the observation of three clusters associated with these traits, composed of subshrub, shrub, arboreal and/or herbaceous species. The shared traits underscore the evolutionary association between traits and the environment. Finally, this comprehensive overview of these traits allows us to understand the dynamics of Caatinga plants and serves as a foundation for future analyses of the varying vulnerability of plants within each cluster to climate change.

Elevated Ozone Reduces the Quality of Tea Leaves but May Improve the Resistance of Tea Plants.

Tropospheric ozone (O3) pollution can affect plant nutritional quality and secondary metabolites by altering plant biochemistry and physiology, which may lead to unpredictable effects on crop quality and resistance to pests and diseases. Here, we investigated the effects of O3 (ambient air, Am; ambient air +80 ppb of O3, EO3) on the quality compounds and chemical defenses of a widely cultivated tea variety in China (Camellia sinensis cv. 'Baiye 1 Hao') using open-top chamber (OTC). We found that elevated O3 increased the ratio of total polyphenols to free amino acids while decreasing the value of the catechin quality index, indicating a reduction in leaf quality for green tea. Specifically, elevated O3 reduced concentrations of amino acids and caffeine but shows no impact on the concentrations of total polyphenols in tea leaves. Within individual catechins, elevated O3 increased the concentrations of ester catechins but not non-ester catechins, resulting in a slight increase in total catechins. Moreover, elevated O3 increased the emission of biogenic volatile organic compounds involved in plant defense against herbivores and parasites, including green leaf volatiles, aromatics, and terpenes. Additionally, concentrations of main chemical defenses, represented as condensed tannins and lignin, in tea leaves also increased in response to elevated O3. In conclusion, our results suggest that elevated ground-level O3 may reduce the quality of tea leaves but could potentially enhance the resistance of tea plants to biotic stresses.