Unique and Overlapping Expression Patterns among Members of Photosynthesis-Associated Nuclear Gene Families in Arabidopsis  

Abstract

Light provides crucial positional information in plant development, and the morphogenetic processes that are orchestrated by light signals are triggered by changes of gene expression in response to variations in light parameters. Control of expression of members of the RbcS and Lhc families of photosynthesis-associated nuclear genes by light cues is a paradigm for lightregulated gene transcription, but high-resolution expression profiles for these gene families are lacking. In this study, we have investigated expression patterns of members of the RbcS and Lhc gene families in Arabidopsis (Arabidopsis thaliana) at the cellular level during undisturbed development and upon controlled interference of the light environment. Members of the RbcS and Lhc gene families are expressed in specialized territories, including root tip, leaf adaxial, abaxial, and epidermal domains, and with distinct chronologies, identifying successive stages of leaf mesophyll ontogeny. Defined spatial and temporal overlap of gene expression fields suggest that the light-harvesting and photosynthetic apparatus may have a different polypeptide composition in different cells and that such composition could change over time even within the same cell.

Expression of DOF genes identifies early stages of vascular development in Arabidopsis leaves

“…Available evidence, however, suggests that the selection process terminates with emergence of files of ground cells that have activated expression of the HD-ZIP III gene ATHB8 and that will successively elongate into procambial cells (AlonsoPeral et al, 2006;Candela et al, 2001;Carland and Nelson, 2004;Cnops et al, 2006;Donner et al, 2009;Kang and Dengler, 2004;Koizumi et al, 2000;Petricka and Nelson, 2007;Sawchuk et al, 2007Sawchuk et al, , 2008Scarpella et al, 2004Scarpella et al, , 2006. Therefore, the events preceding acquisition of the ATHB8 preprocambial cell state are crucial for vein formation.…”

“…An unambiguous criterion to test such a hypothesis, however, would be to visualize expression of individual DOF genes and ATHB8 within the same sample. We therefore tested the degree of colocalization between DOF2.1 pro :HTA6:EYFP and ATHB pro :ECFP-Nuc (Sawchuk et al, 2008), between DOF4.6 pro :HTA6:EYFP and ATHB pro :ECFP-Nuc, and between DOF5.3 pro :mGFP4er and ATHB8 pro :HTA6:EYFP.…”

“…Initiation of ATHB8 expression is directly controlled by MP (Donner et al, 2009), and identifies acquisition of a critical and typically irreversible 'preprocambial' cell state that accurately predicts sites of vascular differentiation (Alonso-Peral et al, 2006;Candela et al, 2001;Carland and Nelson, 2004;Cnops et al, 2006;Donner et al, 2009;Kang and Dengler, 2004;Koizumi et al, 2000;Petricka and Nelson, 2007;Pineau et al, 2005;Sawchuk et al, 2007Sawchuk et al, , 2008Scarpella et al, 2004Scarpella et al, , 2006. A view of the transcriptional landscape of cells at preprocambial stages would be particularly valuable as it might provide insight into the molecular pathways underlying vein formation.…”

Isolation and characterization of strong gene regulatory sequences from apple, Malus × domestica

“…Although the coding regions of different RbcS gene family members are highly similar, the level and pattern of expression can vary considerably (Anisimov et al 2007;Sawchuk et al 2008). The apple RbcS gene we used in this study to isolate regulatory sequences from shows homology to the RbcS1A gene subfamily from Arabidopsis thaliana, which was maximally expressed in differentiating and mature leaf mesophyll cells of Arabidopsis (Sawchuk et al 2008).…”

“…The apple RbcS gene we used in this study to isolate regulatory sequences from shows homology to the RbcS1A gene subfamily from Arabidopsis thaliana, which was maximally expressed in differentiating and mature leaf mesophyll cells of Arabidopsis (Sawchuk et al 2008). Following a genome walking approach, 5′-and 3′-flanking genomic DNA sequences of MdRbcS were amplified, cloned, and characterized.…”