TY  - JOUR
A1  - Martin, Craig E.
A1  - Herppich, Werner B.
A1  - Roscher, Yvonne
A1  - Burkart, Michael
T1  - Relationships between leaf succulence and Crassulacean acid metabolism in the genus Sansevieria (Asparagaceae)
JF  - Flora : morphology, distribution, functional ecology of plants
N2  - Relationships between different measures of succulence and Crassulacean acid metabolism (CAM; defined here as nocturnal increases in tissue acidity) were investigated in leaves of ten species of Sansevieria under greenhouse conditions. CAM was found in seven of the ten species investigated, and CAM correlated negatively with leaf thickness and leaf hydrenchyma/chlorenchyma ratio. Similarly, CAM correlated negatively with leaf water content, but only when expressed on a fresh mass basis. CAM was not correlated with "mesophyll succulence", but weakly with leaf chlorophyll concentration. These results indicate that CAM is associated more with "all-cell succulence" and not with the amount of leaf hydrenchyma in the genus Sansevieria. The findings of this study emphasize the importance of defining the nature of "leaf succulence" in studies of photosynthetic pathways and leaf morphology. Evidence is also provided that CAM and succulence arose multiple times in the genus Sansevieria.
KW  - Anatomy
KW  - CAM
KW  - Chlorenchyma
KW  - Chlorophyll
KW  - Hydrenchyma
KW  - Morphology
KW  - Phylogeny
Y1  - 2019
U6  - https://doi.org/10.1016/j.flora.2019.151489
SN  - 0367-2530
SN  - 1618-0585
VL  - 261
PB  - Elsevier
CY  - München
ER  - 
TY  - JOUR
A1  - Zhao, Liming
A1  - Xia, Yan
A1  - Wu, Xiao-Yuan
A1  - Schippers, Jos H. M.
A1  - Jing, Hai-Chun
T1  - Phenotypic analysis and molecular markers of leaf senescence
JF  - Plant Senescence: Methods and Protocols
N2  - The process of leaf senescence consists of the final stage of leaf development. It has evolved as a mechanism to degrade macromolecules and micronutrients and remobilize them to other developing parts of the plant; hence it plays a central role for the survival of plants and crop production. During senescence, a range of physiological, morphological, cellular, and molecular events occur, which are generally referred to as the senescence syndrome that includes several hallmarks such as visible yellowing, loss of chlorophyll and water content, increase of ion leakage and cell death, deformation of chloroplast and cell structure, as well as the upregulation of thousands of so-called senescence-associated genes (SAGs) and downregulation of photosynthesis-associated genes (PAGs). This chapter is devoted to methods characterizing the onset and progression of leaf senescence at the morphological, physiological, cellular, and molecular levels. Leaf senescence normally progresses in an age-dependent manner but is also induced prematurely by a variety of environmental stresses in plants. Focused on the hallmarks of the senescence syndrome, a series of protocols is described to asses quantitatively the senescence process caused by developmental cues or environmental perturbations. We first briefly describe the senescence process, the events associated with the senescence syndrome, and the theories and methods to phenotype senescence. Detailed protocols for monitoring senescence in planta and in vitro, using the whole plant and the detached leaf, respectively, are presented. For convenience, most of the protocols use the model plant species Arabidopsis and rice, but they can be easily extended to other plants.
KW  - Leaf senescence
KW  - Visible yellowing
KW  - Chlorophyll
KW  - Ion leakage
KW  - Cell death
KW  - Senescence-associated genes (SAGs)
KW  - Arabidopsis
KW  - Rice
Y1  - 2018
SN  - 978-1-4939-7672-0
SN  - 978-1-4939-7670-6
U6  - https://doi.org/10.1007/978-1-4939-7672-0_3
SN  - 1064-3745
SN  - 1940-6029
VL  - 1744
SP  - 35
EP  - 48
PB  - Humana Press Inc.
CY  - Totowa
ER  -