Recent Posts

Identification of putative substrates of SEC2, a chloroplast inner envelope translocase

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Chloroplasts have evolved from photosynthetic bacteria, and genes necessary for chloroplast function have moved from the chloroplast to the nuclear genome of the host eukaryotic cell.  Proteins encoded by these genes are made in the cytosol and imported into the chloroplast using protein translocases. …

The RxLR motif of the Phytophthora infestans effector AVR3a is cleaved before secretion ($)

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RxLR effectors are proteins secreted from pathogens that enter the cells of the host and support the effectiveness of the pathogen in various ways. Their name refers to the sequence RxLR (Arg-Xxx-Leu-Arg). Previously, this sequence has been thought to be involved the effector’s entry into the host…

Review: Making plants break a sweat: the structure, function, and evolution of plant salt glands

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Many agricultural lands are becoming saltier as a consequence of irrigation and sea water incursion, yet most crops are very sensitive to salt. Salt glands that accumulate and secrete salt have evolved independently at least 12 times in plants. Dassanayake and Larkin review the structure, function and…

Division of labor during apical hook formation

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Soon after dicots germinate, the hypocotyl arches into a hook-like structure that protects the shoot apical meristem as the seedling grows through the soil. Once the seedling emerges from the ground and senses light, the hypocotyl straightens. The asymmetric growth that results in apical hook formation…

Ethylene regulates differential growth via BIG ARF-GEF-dependent post-Golgi secretory trafficking in Arabidopsis

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Regulated movement to and from the plasma membrane (PM) has emerged as an important strategy for controlling the activity of plasma membrane proteins such as transporters and receptors. Jonsson et al. investigated the cellular machinery required for the insertion of the auxin-transport protein AUX1 into…

A Raf-like protein kinase BHP mediates blue light-dependent stomatal opening

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How do stomata open in response to blue light?  Blue light is perceived by phototropin receptor kinases that activate BLUE LIGHT SIGNALING1 (BLUS1), type 1 protein phosphatase (PP1), and the plasma membrane (PM) H+-ATPase.  Hayashi et al. screened a commercial kinase inhibitor library to identify the…

Nanoscale movements of cellulose microfibrils in primary cell walls ($)

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Cell walls are complex mixtures of cellulose microfibrils, proteins and other materials. Their mechanical properties can be measured and modeled, but it is not always simple to translate these measurements to changes at the molecular level. Zhang et al. used atomic force microscopy to provide an unprecedented…

Cell-size dependent progression of the cell cycle for homeostasis and flexibility of cell size

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Cell size is determined by growth rate and frequency of division. Studies in yeast revealed mechanisms that coordinate these processes, as well as the crucial checkpoint controls that ensure the cell is “ready” to divide, but can models from single-celled organisms be applied to multicellular ones…

Breakthrough Technologies: Hydroxyproline-rich glycoproteins – bioinformatics and evolution

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A pair of Breakthrough Technology papers in Plant Physiology discusses new tools to identify hydroxyproline-rich glycoproteins and insights into their evolution. Hydroxyproline-rich glycoproteins (HRGPs) are repeat-rich cell wall proteins that have been described as falling into three large families:…