Journal Article

The Craterostigma plantagineum glycine-rich protein CpGRP1 interacts with a cell wall-associated protein kinase 1 (CpWAK1) and accumulates in leaf cell walls during dehydration

Stephanie Krey, Barbara von den Driesch, Dorothea Bartels, Valentino Giarola

2016

Overview

Craterostigma plantagineum tolerates extreme desiccation. Leaves of this plant shrink and extensively fold during dehydration and expand again during rehydration, preserving their structural integrity. Genes were analysed that may participate in the reversible folding mechanism. Analysis of transcripts abundantly expressed in desiccated leaves identified a gene putatively coding for an apoplastic glycine-rich protein (CpGRP1). We studied the expression, regulation and subcellular localization of CpGRP1 and its ability to interact with a cell wall-associated protein kinase (CpWAK1) to understand the role of CpGRP1 in the cell wall during dehydration. The CpGRP1 protein accumulates in the apoplast of desiccated leaves. Analysis of the promoter revealed that the gene expression is mainly regulated at the transcriptional level, is independent of abscisic acid (ABA) and involves a drought-responsive cis-element (DRE). CpGRP1 interacts with CpWAK1 which is down-regulated in response to dehydration. Our data suggest a role of the CpGRP1–CpWAK1 complex in dehydration-induced morphological changes in the cell wall during dehydration in C. plantagineum. Cell wall pectins and dehydration-induced pectin modifications are predicted to be involved in the activity of the CpGRP1–CpWAK1 complex.

• Publisher: New Phytologist Trust,Wiley Subscription Services, Inc
• Subject: Abscisic acid / Abscisic Acid - pharmacology / Amino Acid Sequence / Apoplast / Arabidopsis Proteins - metabolism / Base Sequence / Cell Wall - drug effects / Cell Wall - metabolism / Cell walls / cell wall‐associated protein kinase / Craterostigma - drug effects / Craterostigma - genetics / Craterostigma - metabolism / Craterostigma plantagineum / Dehydration / Desiccation / desiccation tolerance / DNA, Complementary - genetics / DNA, Complementary - isolation & purification / Down-Regulation - drug effects / Drought / Droughts / Electrophoresis, Gel, Two-Dimensional / Gene expression / Gene Expression Regulation, Plant - drug effects / genes / Glycine / Glycine (amino acid) / Glycine - metabolism / glycine‐rich protein / Green Fluorescent Proteins - metabolism / Kinases / leaf folding / Leaves / Localization / Models, Biological / Pectin / pectins / Plant Leaves - drug effects / Plant Leaves - metabolism / plant proteins / Plant Proteins - chemistry / Plant Proteins - genetics / Plant Proteins - metabolism / Promoter Regions, Genetic - genetics / Protein Binding - drug effects / Protein kinase / Protein Kinases - metabolism / Proteins / Recombinant Fusion Proteins - metabolism / Rehydration / resurrection plants / Saccharomyces cerevisiae - metabolism / Sequence Analysis, DNA / Structural integrity / Transcription / transcription (genetics)