TY  - JOUR
A1  - Köslin-Findeklee, Fabian
A1  - Rizi, Vajiheh Safavi
A1  - Becker, Martin A.
A1  - Parra-Londono, Sebastian
A1  - Arif, Muhammad
A1  - Balazadeh, Salma
A1  - Müller-Röber, Bernd
A1  - Kunze, Reinhard
A1  - Horst, Walter J.
T1  - Transcriptomic analysis of nitrogen starvation- and cultivar-specific leaf senescence in winter oilseed rape (Brassica napus L.)
JF  - Plant science : an international journal of experimental plant biology
N2  - High nitrogen (N) efficiency, characterized by high grain yield under N limitation, is an important agricultural trait in Brassica napus L. cultivars related to delayed senescence of older leaves during reproductive growth (a syndrome called stay-green). The aim of this study was thus to identify genes whose expression is specifically altered during N starvation-induced leaf senescence and that can be used as markers to distinguish cultivars at early stages of senescence prior to chlorophyll loss. To this end, the transcriptomes of leaves of two B. napus cultivars differing in stay-green characteristics and N efficiency were analyzed 4 days after the induction of senescence by either N starvation, leaf shading or detaching. In addition to N metabolism genes, N starvation mostly (and specifically) repressed genes related to photosynthesis, photorespiration and cell-wall structure, while genes related to mitochondrial electron transport and flavonoid biosynthesis were predominately up-regulated. A kinetic study over a period of 12 days with four B. napus cultivars differing in their stay-green characteristics confirmed the cultivar-specific regulation of six genes in agreement with their senescence behavior: the senescence regulator ANAC029, the anthocyanin synthesis-related genes ANS and DFR-like1, the ammonium transporter AMT1:4, the ureide transporter UPSS, and SPS1 involved in sucrose biosynthesis. The identified genes represent markers for the detection of cultivar-specific differences in N starvation-induced leaf senescence and can thus be employed as valuable tools in B. napus breeding. (C) 2015 Elsevier Ireland Ltd. All rights reserved.
KW  - Brassica napus
KW  - Genotypic differences
KW  - Leaf senescence
KW  - Molecular marker
KW  - N efficiency
KW  - Stay-green
Y1  - 2015
U6  - https://doi.org/10.1016/j.plantsci.2014.11.018
SN  - 0168-9452
VL  - 233
SP  - 174
EP  - 185
PB  - Elsevier
CY  - Clare
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  -