The Genetic Control of the Compound Leaf Patterning in Medicago truncatula

Simple and compound which are the two basic types of leaves are distinguished by the pattern of the distribution of blades on the petiole. Compared to simple leaves comprising a single blade, compound leaves have multiple blade units and exhibit more complex and diverse patterns of organ organization, and the molecular mechanisms underlying their pattern formation are receiving more and more attention in recent years. Studies in model legume Medicago truncatula have led to an improved understanding of the genetic control of the compound leaf patterning. This review is an attempt to summarize the current knowledge about the compound leaf morphogenesis of M. truncatula, with a focus on the molecular mechanisms involved in pattern formation. It also includes some comparisons of the molecular mechanisms between leaf morphogenesis of different model species and offers useful information for the molecular design of legume crops.

Biomorphological features of floribunda roses leaves and their importance for ornamental gardening

The results of morphometric analysis of the leaves in floribunda roses varieties, such as Pomponella, Lovely Green, Carmagnola, Arthur Bell, Lilli Marleen, Westpoint, Minerva, Novalis, Goldelse, Rotkappchen, Friesia, Lavaglut, Iceberg, Santa Monika, Mathias, Bella Rosa, Cream Abundance, Hans Gonewein, Let's Celebrate and Gebruder Grimm, which have different origins and differ significantly in morphological and decorative characteristics are presented. The studies were conducted during 2018–2021 on the experimental plots of the Department of Landscape Gardening of Uman National University of Horticulture according to the generally accepted method. The description of the morphological traits of the varieties was carried out by the method of visual assessment using measurements and calculations. As a result of the research, it was found that the studied genotypes significantly differ in the biometric parameters of the compound leaf, features of the surface of leaf blades, their shape and size. The highest leaf blades areas were noted in the varieties Novalis 15.1 сm2, Rotkappchen 12.0 cm2 and Pomponella 11.8 cm2. The lowest biometric traits of the leaf were recorded in the varieties Santa Monika, whose compound leaf length is 9.2 cm, Mathias 9.1 cm, Bella Rosa 10.8 cm and Cream Abundance 9.8 cm. The size of the leaf, its shape, color and gloss, are important for the overall impression of the planting object and determine the decorative value of the respective variety. Of all the varieties, Westpoint, Rotkappchen, Hans Gonewein, and Gebruder Grimm have the glossiest leaves. The bright shine together with dark green color of the leaves of these varieties make their bushes more expressive and bright and, therefore, more attractive for use in ornamental gardening. The results of the study are of practical importance, since they make it possible to select varieties that are valuable for ornamental gardening, not only in decorativeness of the flower, but also in the characteristics of their leaf appearance.

Carbon absorption capability of single-leaf and compound-leaf plants in the BNI Urban Forest, Banda Aceh

The creation of Open Green Spaces is one of the options for mitigating the impact of global warming. In order to maximize the function of urban forests as carbon dioxide absorbers, plant species selection for urban forests must be considered. The goal of this study was to compare the ability of single-leaf and compound-leaved plants growing in urban forests to absorb carbon dioxide. Exploratory survey methods with purposive sampling were used. The single-leaf plant, B. asiatica (520 cm2), had the maximum leaf area, whereas the single-leaf species, M. elengi had the lowest leaf area (47.50 cm2). The plant with the highest water content in leaves was found in single-leaf plants, B. asiatica (ranging from 74.67 percent to 77.32 percent), while plant F.decipiens from the compound-leaf plant had the lowest water content (ranging from 44.34 percent to 46.14 percent). The plant with the highest percentage of carbohydrate mass at 06.00 am was M. elengi (531.63 percent), and the plant with the lowest percentage of carbohydrate mass was P.indicus (211.15 percent). At 11 am, the compound-leaf plant S.mahogani (496.76 percent) had the largest percentage of carbohydrate mass, B.asiatica had the lowest (289.29 percent). B.asiatica had the most carbon dioxide absorption per leaf area per hour (g/leaf/hour), whereas S. mahogany had the lowest. S.mahogani (32.514 Å) had the highest chlorophyll concentration in the 06.00 am sample, while P.indicus had the highest chlorophyll concentration in the 11.00 am sample (42.440 Å).

The WOX family transcriptional regulator SlLAM1 controls compound leaf and floral organ development in Solanum lycopersicum

Plant specific WOX family transcription factors play important roles from embryogenesis to lateral organ development. The WOX1 transcription factors, belonging to the modern clade of WOX family, are found to regulate leaf blade outgrowth specifically in the mediolateral axis. However, the role of WOX1 in compound leaf development is still unknown. Phylogenetic analysis of the whole WOX family in tomato indicates that there are 10 members that represent the modern, intermediate, and ancient clades. Using phylogenetic analysis and a reverse genetic approach, we identified the modern clade SlLAM1 gene from tomato and analyzed its function and tissue specific expression pattern. Here, we show that knocking out SlLAM1 via CRISPR/Cas9-mediated genome editing led to narrow leaves, and reduced number of secondary leaflets. Overexpression of tomato SlLAM1 could rescue the defect of tobacco lam1 mutant. Anatomical and transcriptomic analyses demonstrated that floral organ development, fruit size, secondary leaflet initiation, and leaf complexity were altered due to loss-of-function of SlLAM1. These findings elucidate that tomato SlLAM1 plays an important role in the regulation of secondary leaflet initiation, in addition to its conserved function in blade expansion.

Collaboration of multiple pathways in making a compound leaf

SummaryThe variability in leaf form in nature is immense. Leaf patterning occurs by differential growth that occurs during a limited window of morphogenetic activity at the leaf marginal meristem. While many regulators have been implicated in the designation of the morphogenetic window and in leaf patterning, how these effectors interact to generate a particular form is still not well understood.We addressed the interaction among different effectors of tomato compound leaf development, using genetic and molecular analyses.Mutations in the tomato auxin response factor SlARF5/SlMP, which promotes leaflet formation, suppressed the increased leaf complexity of mutants with extended morphogenetic window. Impaired activity of the NAC/CUC transcription factor GOBLET (GOB), which specifies leaflet boundaries, also reduced leaf complexity in these backgrounds. Analysis of genetic interactions showed that the patterning factors SlMP, GOB and the MYB transcription factor LYRATE (LYR) act in parallel to promote leaflet formation.This work places an array of developmental regulators in a morphogenetic context. It reveals how organ-level differentiation rate and local growth are coordinated to sculpture an organ. These concepts and findings are applicable to other plant species and developmental processes that are regulated by patterning and differentiation.