Eukaryotic genes contain protein-coding exons interspersed with non-coding introns. While introns are usually spliced out of mRNA (often in conjunction with various exons), intron retention usually causes mRNA to remain in the nucleus instead of being exported to the cytoplasm for translation. This process stalls gene expression at a particular stage, tissue, or condition, thereby […]
Roots grow into new regions of the soil in their constant quest for water and dissolved minerals. This crucial task is made possible by the root meristem and stem cell niche, where neatly arranged stem cells quickly divide beneath a protective root cap. Stem cells give rise to transit amplifying cells, which undergo several quick […]
Plants have two major ways of dealing with drought stress. First, when water levels are low, the phytohormone abscisic acid (ABA) induces stomatal closure. Soon after, growth, flowering, and fruit development take a back seat to plant survival. This suppressed growth is mediated by decreased activity of the growth-promoting hormone gibberellin (GA). Under stress conditions, […]
A beam of sunlight sends Chlamydomonas reinhardtii scrambling. This tiny, biflagellate alga senses light with its eyespot and adjusts its movements accordingly, depending on photosynthetic needs. In the eyespot, a membranous structure of reddish, carotenoid-filled granules that reflect light and two photoreceptors orchestrate the light guidance of the alga. Two well-characterized photoreceptors, channelrhodopsin 1 (ChR1) […]
Ornamental grasses with a sprawling growth habit may be welcome in the garden, but grasses such as maize (Zea mays) give the highest yields when they exhibit upright leaf architecture, allowing them to be planted at high density while maximizing their exposure to sunlight. The maize leaf is composed of a stem-gripping proximal sheath and […]
A lot of effort goes into making a flower. Suites of genes must function in the right place at the right time. If not, stamens might grow where sepals should be, and so on, yielding homeotic mutant flowers. In general, flower parts are arranged in four concentric whorls of organs, including (from outside to inside) […]
Plants produce scores of specialized metabolites (SMs) to attract or repel the organisms around them and to cope with life in a variable environment. For thousands of years, we have been exploiting these compounds to feed, heal, and adorn us. Many more SMs remain to be discovered: the chemical constituents of only 15% of the […]
IN BRIEF by Jennifer Lockhart jlockhart@aspb.org Plant cell components that are no longer needed are degraded in the vacuole, but they don’t get there by magic. Sack-like double-membrane structures called autophagosomes engulf this cellular rubbish and neatly transport it to the vacuole for degradation. Autophagy, a highly conserved process orchestrated by a suite of evolutionarily […]