Patterns of leaf development in anisophyllous shoots

1992 ◽  
Vol 70 (4) ◽  
pp. 676-691 ◽  
Author(s):  
Nancy G. Dengler

Comparisons of the development of the dimorphic leaves of anisophyllous shoots can be used to understand how ontogenies might be modified during evolution to produce morphological change. In anisophyllous shoots, leaves of different sizes are borne on the dorsal and ventral sides of plagiotropic stems. Anisophylly is regarded as an adaptation for light interception in strongly shaded habitats since the small size of dorsal leaves and orientation of leaf blades minimizes self-shading. Anisophylly affects not only the patterns of leaf development, but also shoot symmetry, phyllotaxis, and bud development. Pronounced anisophylly is widely distributed throughout the land plants as a result of convergent evolution, possibly in response to similar selection pressures. In taxa where the expression of anisophylly is fixed, leaf primordium size and correlated characters, including the development of procambium, differ between dorsal and ventral sides of the shoot from the first plastochron. In contrast, patterns of dorsal and ventral leaf growth and correlated characteristics diverge late in development, often at the time leaves expand from the bud, in taxa where the expression of anisophylly is facultative. These observations indicate that changes in the timing of developmental events can account for many, but not all, of the ontogenetic alterations that result in divergent leaf size and shape on the same shoot and, by implication, accompany the evolution of new taxa. Key words: leaf development, anisophylly, heterochrony.

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Chen Luo ◽  
Shenglin Wang ◽  
Kang Ning ◽  
Zijing Chen ◽  
Yixin Wang ◽  
...  

AbstractLeaf size and flatness directly affect photosynthesis and are closely related to agricultural yield. The final leaf size and shape are coordinately determined by cell proliferation, differentiation, and expansion during leaf development. Lettuce (Lactuca sativa L.) is one of the most important leafy vegetables worldwide, and lettuce leaves vary in shape and size. However, the molecular mechanisms of leaf development in lettuce are largely unknown. In this study, we showed that the lettuce APETALA2 (LsAP2) gene regulates leaf morphology. LsAP2 encodes a transcriptional repressor that contains the conserved EAR motif, which mediates interactions with the TOPLESS/TOPLESS-RELATED (TPL/TPR) corepressors. Overexpression of LsAP2 led to small and crinkly leaves, and many bulges were seen on the surface of the leaf blade. LsAP2 physically interacted with the CINCINNATA (CIN)-like TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) transcription factors and inhibited their transcriptional activation activity. RNA sequencing analysis showed that LsAP2 affected the expression of auxin- and polarity-related genes. In addition, LsAP2 directly repressed the abaxial identity gene KANADI2 (LsKAN2). Together, these results indicate that LsAP2 regulates leaf morphology by inhibiting CIN-like TCP transcription factors and repressing LsKAN2, and our work provides insights into the regulatory mechanisms of leaf development in lettuce.


1991 ◽  
Vol 69 (3) ◽  
pp. 489-493
Author(s):  
Scott Zona

Leaf size and shape, long used to differentiate taxa in Haenianthus, were found to be less useful than previously believed. Nevertheless, two species can be recognized on the basis of leaf shape, H. incrassatus and H. salicifolius. The former species has long petioles, attenuate leaf bases, and thin laminas and is endemic to cloud forests of Jamaica. The latter species, with short petioles, acute to acuminate leaf bases, and thick laminas, has two varieties, H. salicifolius var. salicifolius of Cuba and Haiti, and H. salicifolius var. obovatus of Cuba, Hispaniola, and Puerto Rico. Key words: Caribbean, Haenianthus, morphometric analysis, Oleaceae.


2019 ◽  
Vol 71 (8) ◽  
pp. 2365-2378 ◽  
Author(s):  
Jasmien Vercruysse ◽  
Alexandra Baekelandt ◽  
Nathalie Gonzalez ◽  
Dirk Inzé

Abstract Leaves are the primary organs for photosynthesis, and as such have a pivotal role for plant growth and development. Leaf development is a multifactorial and dynamic process involving many genes that regulate size, shape, and differentiation. The processes that mainly drive leaf development are cell proliferation and cell expansion, and numerous genes have been identified that, when ectopically expressed or down-regulated, increase cell number and/or cell size during leaf growth. Many of the genes regulating cell proliferation are functionally interconnected and can be grouped into regulatory modules. Here, we review our current understanding of six important gene regulatory modules affecting cell proliferation during Arabidopsis leaf growth: ubiquitin receptor DA1–ENHANCER OF DA1 (EOD1), GROWTH REGULATING FACTOR (GRF)–GRF-INTERACTING FACTOR (GIF), SWITCH/SUCROSE NON-FERMENTING (SWI/SNF), gibberellin (GA)–DELLA, KLU, and PEAPOD (PPD). Furthermore, we discuss how post-mitotic cell expansion and these six modules regulating cell proliferation make up the final leaf size.


Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 315
Author(s):  
Hailin Liu ◽  
Xin Han ◽  
Jue Ruan ◽  
Lian Xu ◽  
Bing He

The final size of plant leaves is strictly controlled by environmental and genetic factors, which coordinate cell expansion and cell cycle activity in space and time; however, the regulatory mechanisms of leaf growth are still poorly understood. Ginkgo biloba is a dioecious species native to China with medicinally and phylogenetically important characteristics, and its fan-shaped leaves are unique in gymnosperms, while the mechanism of G. biloba leaf development remains unclear. In this study we studied the transcriptome of G. biloba leaves at three developmental stages using high-throughput RNA-seq technology. Approximately 4167 differentially expressed genes (DEGs) were obtained, and a total of 12,137 genes were structure optimized together with 732 new genes identified. More than 50 growth-related factors and gene modules were identified based on DEG and Weighted Gene Co-expression Network Analysis. These results could remarkably expand the existing transcriptome resources of G. biloba, and provide references for subsequent analysis of ginkgo leaf development.


1996 ◽  
Vol 351 (1348) ◽  
pp. 1671-1677 ◽  

Leaves display an enormous array of sizes and shapes. Although these attributes appear to have evolved primarily in response to abiotic conditions in the plant’s habitat, the importance of insect herbivores as additional selective agents is still poorly understood. A necessary requirem ent for leaf size and shape to evolve in response to attack by insects is that insects must respond to and/or be affected by, leaf morphology. We tested leaf-shape preferences in adult flea beetles ( Phyllotreta spp.) feeding on the highly variable rosette leaves of Capsella bursa-pastoris . Contrary to theoretical expectation (Brown & Lawton 1991), leaves with deeply lobed margins were more intensely damaged, both in field-collected and experimental plants. In two ancillary experiments with Capsella , we found that Spodoptera caterpillars showed no preferences for leaf shape, but that adult vine weevils ( Otiorhynchus sulcatus ) did, preferring (as predicted), undivided over divided leaves. We conclude that Brown & Law ton’s (1991) hypothesis is at best weakly supported by laboratory data for vine weevils, refuted by laboratory data for Spodoptera , and consistently refuted by both laboratory and field data for flea beetles. Although the experiment tried to reduce confounding variables to a minimum, interpretation was complicated by correlations between leaf shape and other developmental parameters of the plants, and highlights the difficulty of disentangling leaf-shape effects from other confounding factors.


2009 ◽  
Vol 151 (4) ◽  
pp. 1844-1854 ◽  
Author(s):  
Jennifer Sloan ◽  
Andreas Backhaus ◽  
Robert Malinowski ◽  
Simon McQueen-Mason ◽  
Andrew J. Fleming
Keyword(s):  

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Kaiye Yu ◽  
Jinshe Wang ◽  
Chongyuan Sun ◽  
Xiaoqian Liu ◽  
Huanqing Xu ◽  
...  

Abstract Background Leaf size and shape, which affect light capture, and chlorophyll content are important factors affecting photosynthetic efficiency. Genetic variation of these components significantly affects yield potential and seed quality. Identification of the genetic basis for these traits and the relationship between them is of great practical significance for achieving ideal plant architecture and high photosynthetic efficiency for improved yield. Results Here, we undertook a large-scale linkage mapping study using three mapping populations to determine the genetic interplay between soybean leaf-related traits and chlorophyll content across two environments. Correlation analysis revealed a significant negative correlation between leaf size and shape, while both traits were positively correlated with chlorophyll content. This phenotypic relationship was verified across the three mapping populations as determined by principal component analysis, suggesting that these traits are under the control of complex and interrelated genetic components. The QTLs for leaf-related traits and chlorophyll are partly shared, which further supports the close genetic relationship between the two traits. The largest-effect major loci, q20, was stably identified across all population and environments and harbored the narrow leaflet gene Gm-JAG1 (Ln/ln), which is a key regulator of leaflet shape in soybean. Conclusion Our results uncover several major QTLs (q4–1, q4–2, q11, q13, q18 and q20) and its candidate genes specific or common to leaf-related traits and chlorophyll, and also show a complex epistatic interaction between the two traits. The SNP markers closely linked to these valuable QTLs could be used for molecular design breeding with improved plant architecture, photosynthetic capacity and even yield.


AoB Plants ◽  
2019 ◽  
Vol 11 (6) ◽  
Author(s):  
Jun Sun ◽  
Mantang Wang ◽  
Min Lyu ◽  
Karl J Niklas ◽  
Quanlin Zhong ◽  
...  

Abstract The trade-off between leaf number and individual leaf size on current-year shoots (twigs) is crucial to light interception and thus net carbon gain. However, a theoretical basis for understanding this trade-off remains elusive. Here, we argue that this trade-off emerges directly from the relationship between annual growth in leaf and stem mass, a hypothesis that predicts that maximum individual leaf size (i.e. leaf mass, Mmax, or leaf area, Amax) will scale negatively and isometrically with leafing intensity (i.e. leaf number per unit stem mass, per unit stem volume or per stem cross-sectional area). We tested this hypothesis by analysing the twigs of 64 species inhabiting three different forest communities along an elevation gradient using standardized major axis (SMA) analyses. Across species, maximum individual leaf size (Mmax, Amax) scaled isometrically with respect to leafing intensity; the scaling constants between maximum leaf size and leafing intensity (based on stem cross-sectional area) differed significantly among the three forests. Therefore, our hypothesis successfully predicts a scaling relationship between maximum individual leaf size and leafing intensity, and provides a general explanation for the leaf size-number trade-off as a consequence of mechanical-hydraulic constraints on stem and leaf growth per year.


Plants ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 243 ◽  
Author(s):  
Yuanyuan Xiong ◽  
Yuling Jiao

Leaves, the primary plant organs that function in photosynthesis and respiration, have highly organized, flat structures that vary within and among species. In recent years, it has become evident that auxin plays central roles in leaf development, including leaf initiation, blade formation, and compound leaf patterning. In this review, we discuss how auxin maxima form to define leaf primordium formation. We summarize recent progress in understanding of how spatial auxin signaling promotes leaf blade formation. Finally, we discuss how spatial auxin transport and signaling regulate the patterning of compound leaves and leaf serration.


1986 ◽  
Vol 64 (11) ◽  
pp. 2645-2649 ◽  
Author(s):  
E. K. Merrill

Green ash (Fraxinus pennsylvanica var. subintegerrima) seedlings are heteroblastic; during development they produce two types of leaves, simple and compound. When grown under controlled conditions, the sequence of leaf types is predictable. Simple leaves are always at the first four nodes; compound leaves are always at node 8 and above. Nodes 5 through 7 have progressively fewer simple leaves and more compound leaves. Leaf growth on seedlings meets the preconditions of the plastochron index and leaf plastochron index. These indices, as well as the length of single expanding leaves, can be used to predict lengths of leaf primordia at nodes 4 and 8 so that early, simple and compound leaf development can be compared in further studies of green ash.


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