Cell death in maize

Abstract

Cell death occurs in plants as a part of normal development and as a response to toxins, pathogens and other environmental stimuli or insults. When cell death occurs as an orderly disassembly of the cell under the control of a genetically determined program, the process is referred to as programmed cell death (PCD). The PCD mechanisms of plants show many striking similarities to, but also intriguing differences from, those of animals. The extensive genetic, developmental and physiological characterizations of maize have made it an excellent system for the study of cell death. We describe the recent advances in the study of cell death in maize in light of what is known in plants and animals.

Aspartyl Protease-Mediated Cleavage of BAG6 Is Necessary for Autophagy and Fungal Resistance in Plants

“…In the BAG6-overexpressing lines, these lesions appeared as small translucent flecks in younger leaves but coalesced to cover entire leaves as they matured (Figure 1). A similar phenotype was observed following the overexpression of Arabidopsis BAG6 in tobacco (Nicotiana tabacum) in a light-dependent manner (Supplemental Figure 4); light sensitivity is known as an important environmental factor affecting lesion mimic development (Johal et al, 1995;Hu et al, 1998;Buckner et al, 2000). The position of the tag did not affect lesion development, as similar phenotypes were observed with C-terminal fusions (Supplemental Figure 3).…”

“…Lesion mimic mutant phenotypes are observed when plants exhibit disease (lesions) symptoms in the absence of a pathogen (Lorrain et al, 2003). Numerous phenotypes have been described in association with lesion mimics in many plant species (Dangl et al, 1996;Buckner et al, 2000;Zeng et al, 2004). In the BAG6-overexpressing lines, these lesions appeared as small translucent flecks in younger leaves but coalesced to cover entire leaves as they matured (Figure 1).…”

Identification of a Maize Locus That Modulates the Hypersensitive Defense Response, Using Mutant-Assisted Gene Identification and Characterization

“…We are also currently working to construct B73 near isogenic lines differing for Hrml1 We will further cross them to lines carrying other Rp1 alleles to confirm that this locus also modifies the wild-type Rp1-mediated response. It also remains to be determined whether Hrml1 modulates cell-death phenotypes conferred by other major, HRconferring, maize disease-resistance genes such as Rxo , other Rp genes (e.g., Webb et al 2002), and Rpp genes (Storey and Howland 1957;Futrell et al 1975;Chen et al 2004) and possibly also by non-HR causes of programmed cell death (Buckner et al 2000).…”

The self-incompatibility response in Papaver rhoeas pollen causes early and striking alterations to organelles

“…Not all, but some, of these features are also distinctive for PCD in plant cells. 28 Biochemical events include: cleavage of DNA into nucleosomal fragments, caspase activation, cytochrome c leakage from mitochondria, activation of key antiapoptotic genes, such as BCL2. Chromatin condensation and shrinkage of the nucleus are observed in many plant cell types undergoing PCD.…”

“…Chromatin condensation and shrinkage of the nucleus are observed in many plant cell types undergoing PCD. 28,29 Like animal cells cytoplasmic condensation and shrinkage usually accompany PCD. 28 Other morphological changes frequently associated with PCD include the swelling or condensation of mitochondria and the dilatation of endoplasmic reticulum (ER).…”