Morpho-anatomical studies on the leaf reduction in Casuarina: the ecology of xeromorphy

Dörken, Veit Martin; Parsons, R. F.

doi:10.1007/s00468-017-1535-5

Cited by 16 publications

(24 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…sun leaves possessing a higher leaf thickness and mass, a higher stomatal density, multi‐layered palisade parenchyma and weakly developed spongy parenchyma. However, the situation in sun leaves of A. alba differs in one major point: Typically, the leaf size of especially evergreen plants ‐ angiosperms and gymnosperms as well ‐ growing under xeric conditions is characterized by a strong leaf reduction as a morphological response to reduce the water loss via the lamina in times of water deficit (Blum, ; Blum & Arkin, ; Bosabalidis & Kofidis, ; Dörken & Parsons, , ; Dörken, Parsons, & Marshall, ; Parsons, ; Seidling, Ziche, & Beck, ; Thoday, ). Thus, in light exposed parts of the crown strongly reduced leaves were expected also for A. alba .…”

Section: Discussionmentioning

confidence: 99%

Morpho‐anatomical and physiological differences between sun and shade leaves in Abies alba Mill. (Pinaceae, Coniferales): a combined approach

Dörken

Lepetit

2018

Plant Cell & Environment

View full text Add to dashboard Cite

Morphology, anatomy and physiology of sun and shade leaves of Abies alba were investigated and major differences were identified, such as sun leaves being larger, containing a hypodermis and palisade parenchyma as well as possessing more stomata, while shade leaves exhibit a distinct leaf dimorphism. The large size of sun leaves and their arrangement crowded on the upper side of a plagiotropic shoot leads to self-shading which is explainable as protection from high solar radiation and to reduce the transpiration via the lamina. Sun leaves furthermore contain a higher xanthophyll cycle pigment amount and Non-Photochemical Quenching (NPQ) capacity, a lower amount of chlorophyll b and a total lower chlorophyll amount per leaf, as well as an increased electron transport rate and an increased photosynthesis light saturation intensity. However, sun leaves switch on their NPQ capacity at rather low light intensities, as exemplified by several parameters newly measured for conifers. Our holistic approach extends previous findings about sun and shade leaves in conifers and demonstrates that both leaf types of A. alba show structural and physiological remarkable similarities to their respective counterparts in angiosperms, but also possess unique characteristics allowing them to cope efficiently with their environmental constraints.

show abstract

Section: Discussionmentioning

confidence: 99%

Morpho‐anatomical and physiological differences between sun and shade leaves in Abies alba Mill. (Pinaceae, Coniferales): a combined approach

Dörken

Lepetit

2018

Plant Cell & Environment

View full text Add to dashboard Cite

show abstract

“…Fig B). The transfusion tissue extending from the xylem lies between this cell layer and the mesophyll cells similarly to the situation in Casuarina and Allocasuarina where the layer has been termed a “foot layer” (Dörken & Parsons ; Dörken et al. ).…”

Section: Discussionmentioning

confidence: 95%

“…In all members of the Casuarinaceae the leaves are also strongly reduced and fused to the shoot axis. As in Callitris within the Casuarinaceae the cotyledons are still foliar, while the subsequent leaves (species‐specific 4‐16 leaves per node) are strongly reduced (Hwang & Conran ; Dörken & Parsons ; Dörken et al. ).…”

Section: Discussionmentioning

confidence: 99%

“…The timing of leaf reduction varies markedly with species. It can occur after years as is the case within several Cupressus species (Cupressaceae, Coniferales) or it can occur in the earliest developmental stages as is the case with all members of the angiosperm family Casuarinaceae (Fagales), where the primary leaves are already strongly reduced scales and all subsequent leaves form the phyllichnia typical of the family (Hwang & Conran ; Dörken & Parsons ; Dörken et al. ).…”

Section: Introductionmentioning

confidence: 99%

“…thick leaves with dense venation, high leaf stiffness) features (compare Hill R.S. ; Dörken & Parsons , , ; Dörken et al. , ).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The foliar characters in Callitris (Callitroideae, Cupressaceae s. str.) and their evolutionary and ecological significance

2019

View full text Add to dashboard Cite

The foliar shift from juvenile needle leaves to the mature scale leaves was investigated in five Callitris species. Their habitats range from rainforest to the semi‐arid. In C. macleayana from the most mesic environment the change from needle to scale leaves is variable and juvenile leave are even retained on mature trees. In the other four species there is a rapid change in size and structure to scale leaves. Anatomically the photosynthetic tissue is condensed and stomatal area is limited compared to species with conventional leaves. A hypodermis is most prominent on the abaxial side of the leaves and may play a role in protection from high solar radiation as most species grow in high light areas. While stomata in the four taxa from wet or moderate rainfall areas are freely exposed, those of C. gracilis from semi‐arid habitats are well protected in longitudinal furrows between the decurrent leaves. The reduced leaf area of all species allows close association between the water‐conducting xylem and the stomata that will facilitate rapid leaf conductance. This links with the anisohydric physiology of the genus and the shallow rooting that can take advantage of brief rainfall events for species in arid climates.

show abstract

The foliar change from seedlings to adults in Allocasuarina (Casuarinaceae): the evolutionary and ecological aspects of leaf reduction, xeromorphy and scleromorphy

2018

Self Cite

View full text Add to dashboard Cite

The morpho‐anatomical structure of the adult photosynthetic organs of the Casuarinaceae is unique in plants. We examine the shoot structure of five species from Allocasuarina ‐ the most derived genus in the family. While the cotyledons of seedlings are similar to those of many other plants the subsequent leaves form a whorl of chlorenchymatic tissue fused to the cortex of the articles of segmented branchlets with only the leaf tips free at the apex of each article. Each leaf in the whorl is called a phyllichnium and consists of a vascular trace below the photosynthetic chlorenchyma with sclerenchyma developed within the mesophyll. The branchlets of Allocasuarina are considered xeromorphic as the stomata of most species are restricted to the sides of the furrows formed by the closely appressed edges of the phyllichnia. The scleromorphic foliage of the ancestral Casuarinaceae may have developed from adaptation to nutrient poor soils but was also preadapted to confer drought resistance. The narrow foliage with abundant sclerenchyma, restricted stomatal area and minimal distance from the atmosphere to xylem tissues ensured that the genus could become competitively successful on impoverished soils and be a distinctive component of arid and even mesic woodlands and forests in Australia.

show abstract

Morpho-anatomical studies on the leaf reduction in Casuarina: the ecology of xeromorphy

Cited by 16 publications

References 41 publications

Morpho‐anatomical and physiological differences between sun and shade leaves in Abies alba Mill. (Pinaceae, Coniferales): a combined approach

Morpho‐anatomical and physiological differences between sun and shade leaves in Abies alba Mill. (Pinaceae, Coniferales): a combined approach

The foliar characters in Callitris (Callitroideae, Cupressaceae s. str.) and their evolutionary and ecological significance

The foliar change from seedlings to adults in Allocasuarina (Casuarinaceae): the evolutionary and ecological aspects of leaf reduction, xeromorphy and scleromorphy

Contact Info

Product

Resources

About