Maintenance of Cell Wall Integrity under High Salinity.

Cell wall biosynthesis is a complex biological process in plants. In the rapidly growing cells or in the plants that encounter a variety of environmental stresses, the compositions and the structure of cell wall can be dynamically changed. To constantly monitor cell wall status, plants have evolved cell wall integrity (CWI) maintenance system, which allows rapid cell growth and improved adaptation of plants to adverse environmental conditions without the perturbation of cell wall organization. Salt stress is one of the abiotic stresses that can severely disrupt CWI, and studies have shown that the ability of plants to sense and maintain CWI is important for salt tolerance. In this review, we highlight the roles of CWI in salt tolerance and the mechanisms underlying the maintenance of CWI under salt stress. The unsolved questions regarding the association between the CWI and salt tolerance are discussed.

High-Throughput Phosphorylation Screening and Validation through Ti(IV)-Nanopolymer Functionalized Reverse Phase Phosphoprotein Array.

Protein phosphorylation is one of the most important and widespread molecular regulatory mechanisms that controls almost all aspects of cellular functions in animals and plants. Here, we introduce a novel chemically functionalized reverse phase phosphoprotein array (RP3A) to capture and measure phosphoproteomes. RP3A uses polyamidoamine (PAMAM) dendrimer immobilized with Ti(IV) ions to functionalize nitrocellulose membrane, facilitating specific chelation of phosphoproteins from complex protein samples on the array. Globular, water-soluble Ti(IV)-dendrimer allows the RP3A surface to be highly accessible to phosphoproteins multidimensionally, and the captured phosphoproteins were subsequently detected using the same validated antibodies as in regular reverse-phase protein arrays. The novel chemical strategy demonstrated superior specificity (1:10 000), high sensitivity (fg level), and good quantitative nature ( R2 = 0.99) for measuring phosphoproteins. We further applied quantitative phosphoproteomics followed by RP3A to validate the phosphorylation status of a panel of phosphoproteins in response to environmental stresses in Arabidopsis.