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Linkage between leaf anatomical structure and key leaf economic traits across co-existing species in temperate forests
Background and aims
Leaf economic spectrum is described by key leaf economic traits, such as leaf tissue density (LTD), specific leaf area (SLA) and leaf nitrogen concentration (LNC). It has been suggested that these key leaf economic traits are associated with leaf anatomy. However, few studies have specifically investigated how leaf anatomical structure affects the key leaf economic traits across co-existing species.
Methods
Here, we examined three key leaf traits (LTD, SLA and LNC) and leaf anatomical traits of 102 species in temperate forests.
Results
We observed that the species with high vein fraction per leaf volume/high vein length per leaf area had high LTD. In comparison with vein length per leaf area, vein fraction per leaf volume better explained the variations in LTD across co-existing species. Moreover, the species with high fraction of palisade tissue across transverse section exhibited high LNC. Additionally, a weak correlation between SLA and palisade tissue fraction across transverse section was detected, indicating that co-existing species can maximize light capture and C assimilation by both concurrently increasing SLA and maintaining relatively stable fraction of palisade tissue.
Conclusion
These results indicate that leaf anatomical structure may determine key leaf economic traits. The findings provide an important insight into the leaf economic spectrum from the perspective of leaf anatomical structure.
Journal Article
The art of perception : memoirs of a life in PR
This is the memoir of the man who has been at the forefront of the PR industry for almost fifty years. Robert Leaf, the first executive to bring PR to the Soviet and Chinese governments during the Cold War, has accomplished more than anyone else. He advised corporations and heads of state, rubbed shoulders with some of the twentieth century's most powerful individuals, and controlled some of the biggest news stories of the time. Now, in an age of twenty-four hour news cycles in which global disasters are shared on the most personal levels and events make it from smartphone to headline news in seconds, perception management has never been more essential for individuals and corporations alike. In a memoir which is as informative as it is entertaining, Robert Leaf shares a lifetime's experience in spreading the gospel of PR around the world which will prove invaluable as much for those in PR as to those with an interest in modern media.
Book
Contrasting water, dry matter and air contents distinguish orthophylls, sclerophylls and succophylls (leaf succulents)
Differences in leaf texture (hardness, thickness) distinguish orthophylls (soft leaves), sclerophylls (hard leaves) and (semi)succophylls (water-storing leaves). Texture is controlled by dry matter, water and air contents. Our aim was to a) identify the best index of succulence, b) assess how these three components vary with leaf type, and c) derive bounds for these properties among the four main leaf-texture classes. Eight contrasting species from the Namib Desert, South Africa were assessed for their leaf area (
A
), thickness (
z
), dry mass (
D
), saturated water content (
Q
), and relative volume of dry matter, water and air to derive various indices of leaf texture.
Q
/
A
(=
Q
V
•
z
), where
Q
V
is saturated water storage per unit volume of leaf and
z
is leaf thickness is an ideal index of succulence. Specific leaf area (SLA) is more suitable as an index of hardness (SLA
−1
=
D
/
A
) but only among non-succulents. Rising leaf specific gravity among sclero-orthophylls is due to replacement of air by dry matter but water among succophylls. Collation of 13 worldwide studies showed that orthophylls can be distinguished by a
Q
/
A
≤ 0.45 mg water mm
−2
leaf surface from succophylls with
Q/A
≥ 0.9, such that there is a divergent relationship among plants regarding their water-storing properties. Semi-succophylls can be defined as having a
Q
/
A
> 0.45 to < 0.9, and sclerophylls can be separated from orthophylls by a SLA ≤ 10 mm
2
mg
−1
dry mass. The distribution of these leaf texture classes may vary greatly within, and especially between, local floras.
Journal Article
Global patterns of leaf construction traits and their covariation along climate and soil environmental gradients
• Leaf functional traits and their covariation underlie plant ecological adaptations along environmental gradients, but there is limited information on the global covariation patterns of key leaf construction traits.
• To explore how leaf construction traits co-vary across diverse climate and soil environmental conditions, we compiled a global dataset including cell wall mass per unit leaf mass (CWmass), leaf carbon (C) and calcium (Ca) concentrations, and specific leaf area (SLA) for 2348 angiosperm species from 340 sites world-wide.
• Our results demonstrated negative correlations between leaf C and Ca concentrations and between leaf C and SLA across diverse nongraminoid angiosperms. Leaf C concentration increased with increasing mean annual temperature (MAT) and mean annual precipitation (MAP) and with decreasing soil pH and calcium carbonate (CaCO₃) concentration, whereas leaf Ca concentration and SLA exhibited the opposite responses to these environmental variables. The covariations of leaf Ca–C and of leaf SLA–C were stronger in habitats with lower MAT and MAP, and/or higher soil CaCO₃ content.
• This global-scale analysis demonstrates that the leaf C and Ca concentrations and SLA together govern the C and biomass investment strategies in leaves of nongraminoids. We conclude that environmental conditions strongly shape leaf construction traits and their covariation patterns.
Journal Article
Molecular characterization of novel bipartite begomovirus associated with enation leaf disease of Garden croton (Codiaeum variegatum L.)
Garden croton (
Codiaeum variegatum
L.) plants showing typical begomovirus symptoms of vein twisting, enation and curling were collected from different gardens at Varanasi, Uttar Pradesh state of India ranged from 20 to 30%. All the 10 ten (CR1-CR10) infected samples of garden croton resulted in expected amplicon of 1.2 Kb in PCR specific to begomoviruses. No amplification was obtained for betasatellite and alphasatellite specific primers. The complete genome sequence of DNA-A and DNA-B for two isolates (CR1 and CR2) was obtained through rolling cycle amplification (RCA) and comparisons were made with other begomoviruses using Sequence Demarcation Tool (SDT) which revealed that, DNA-A of two isolates, CR1 (Acc.No.: MW816855) and CR2 (Acc.No.: MW816856) showed maximum nucleotide (nt) identity of 85.7–85.9% with
Tomato leaf curl Karnataka virus,
which is below the threshold percentage of begomovirus species demarcation, hence considered as novel begomovirus and proposed the name
Garden croton enation leaf curl virus
(CroELCuV) [IN: Varanasi: Croton: 18]. Further, DNA-B these isolates shared maximum nt identity of 91.0–92.2% (DNA-B) with
Tomato leaf curl New Delhi virus
. Recombination and GC plot analysis showed that the recombination occured at in low GC content regions of DNA-A and DNA-B of the CroELCuV and are derived from the previously reported several begomoviruses. This is the first record of novel bipartite begomovirus associated with vein twisting, enation and leaf curling of disease of garden garden croton in India and world.
Journal Article
Overview of molecular mechanisms of plant leaf development: a systematic review
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.
Journal Article
Exploration of the intricacies of low light-induced changes in cigar leaf anticlinal growth: a holistic approach from anatomical and hormonal levels to gene expression
Cigar tobacco stands as a pivotal economic crop, with its leaf growth and development profoundly influenced by light intensity. Present study specifically aimed to investigate how leaf morphology and anticlinal growth responds to varying light intensities, including normal light intensity (NL–300 µmol m
− 2
s
− 1
) and lower light intensity (LL–100 µmol m
− 2
s
− 1
). The research elucidates significant morphological shifts in cigar tobacco leaves under LL, revealing significant alterations in leaf area, leaf length, and leaf width. Early reductions in leaf dimensions, ranging from 30 to 48%, were succeeded by a substantial enhancement in expansion rates from day 9 to day 26, contributing to expanded leaf surfaces at later stages. Upper epidermis thickness declined by 29 − 19%, with a notably slower expansion rate in the initial 20 days. Palisade cell length consistently decreased by 52 − 17%, corresponding with upper epidermis trends. Spongy tissue thickness was reduced by 31 − 12%, with a slower expansion rate in LL for the initial 14 days, and leaf thickness dropped by 34 − 11%. LL resulted in slower leaf anticlinal expansion, leading to reduced leaf thickness (LT). LL significantly influenced phytohormones in cigar tobacco leaves. Gibberellic acid (41–16%) and auxin (20–35%) levels were found in higher amounts, while cytokinin levels (19–5%) were lowered compared to NL, indicating the intricate regulatory role of light in hormonal dynamics. The observed increase in LT and different cell layers at specific time points (day 8, day 12, day 24, and day 28) under LL, although lower than NL, may be attributed to elevated expression of genes related to cell expansion, including
Nt
GRF1
,
Nt
XTH
, and
Nt
SAUR19
at those time points. This comprehensive understanding elucidates the intricate mechanisms by which light intensity orchestrates the multifaceted processes governing leaf anatomy and anticlinal expansion in cigar tobacco plants.
Journal Article
Warming Responses of Leaf Morphology Are Highly Variable among Tropical Tree Species
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.
Journal Article