Signal Transduction of Plant Organ Senescence and Cell Death

Senescence of plant organs, the last stage of organ development, is a form of postmitotic senescence. It is characterized by the functional transition from nutrient assimilation to nutrient remobilization, which is crucial for plant fitness. The initiation and progression of organ senescence are controlled by a variety of internal and external factors such as age, phytohormones and environmental stresses. Significant breakthroughs in deciphering the molecular mechanisms underlying organ senescence have been achieved through the identification of mutants with altered senescence by forward genetic screening and the functional assessment of hundreds of senescence-associated genes (SAGs) by reverse genetic research in the model plant Arabidopsis thaliana as well as in crop plants. Organ senescence involves highly complex genetic programs that are tightly coordinated through multiple levels of regulation, including chromatin and transcriptional regulation as well as posttranscriptional, translational, and posttranslational regulation. Because leaf organ senescence has significant effects on photosynthesis, nutrient mobilization, stress responses, and productivity, many efforts have been made to develop strategies to influence the onset and progression of leaf senescence based on known senescence regulatory mechanisms, with the goal of increasing crop yield, quality, or horticultural performance. However, the nature of organ age, functional property, coordination between different regulatory pathways, source-sink relationship and nutrient remobilization, and anterograde/retrograde signal transduction during organ senescence remain to be unraveled.

This Research Topic aims to gather new information on signaling pathways regulating organ senescence (including leaf, flower, root, seed) in model plants and crop and horticultural plants. This includes molecular and cellular mechanisms associated with known and novel senescence-regulating signals, such as signal perception, receptor activation, phosphorylation, and transcriptional activation/repression. Interactions between different signaling pathways, interactions between different organelles, and interactions between known senescence regulators are of particular interest to this Research Topic. Original papers, reviews and Mini Review on molecular biology, cell biology, physiology, biochemistry, genomics, systems biology and mathematical modeling are solicited for this research topic. Articles should address the following aspects of organ senescence (leaf, flower, root, seed, etc.):

- Novel signaling components regulating organ senescence;
- Communication between different signaling pathways during organ senescence;
- Signal transduction between organs important in senescence;
- Role of different organelles in cell senescence;
- Transcriptional regulation of organ senescence;
- Epigenetic regulation of cell senescence;
- Control of protein stability during organ senescence;
- Nutrient remobilization of cell senescence.