A ROLE FOR CLASP IN MICROTUBULE STABILIZATION
In animals, members of the ORBIT/MAST/CLASP family of microtubule-associated proteins associate with the plus ends of microtubules. Known functions include promoting the addition of tubulin subunits into attached kinetochore fibers during mitosis and stabilizing microtubules in the vicinity of the plasma membrane during interphase. Ambrose et al. (pages 2763–2775) show that the CLASP ortholog in plant cells localizes to microtubules at all stages of the cell cycle and shows enrichment at the growing plus ends. CLASP most likely contributes to cell division, cell expansion, organ morphology, and axial extension in plants through its role in stabilizing microtubules. The cover image highlights microtubule arrays at key stages of the cell cycle in epidermal cells of an Arabidopsis root tip. Ambrose et al. report on the consequences of knocking out CLASP at each of these stages.
PJ:中国科大揭示调控根系发育的新机制
植物体内可以合成许多小的分泌型肽物质，他们可以被细胞表面的 receptor-like kinase (RLK) 识别。本研究发现SERINE RICH ENDOGENOUS PEPTIDE (SCOOP) immune peptides通过调控 PIN-FORMED (PIN)介导的生长素的转运来影响跟的发育。用SCOOP4 and SCOOP12处理会破坏根系的向地性生长、生长素的分布以及PIN的丰度。
分析显示SCOOP4 and SCOOP12被受体MALE DISCOVERER1-INTERACTING RECEPTOR LIKE KINASE2 (MIK2) 识别并通过下游的mitogen-activated kinase MPK6发挥作用. MPK6 可以直接磷酸化PIN 蛋白，从而影响了生长素的转运。
小结：本研究揭示了一个肽类物质通过影响生长素来调控根系发育的机制。
原文：The SCOOP-MIK2 immune pathway modulates Arabidopsis root growth and development by regulating PIN-FORMED abundance and auxin transport
