“Weeds are a fact of life for farmers around the world,” writes Kniss in this analysis of herbicide-use trends. He stresses the limitation of reports that measure only the weight of herbicides used, as there is tremendous variation in the toxicity of different herbicides. He shows that although herbicide use intensity has risen, for many […]
Most fruits form after pollination, making their production vulnerable to pollinator presence. Parthenocarpy is the development of fruit that occurs in the absence of pollination. Genes that enable parthenocarpy have been identified, including a tomato gene involved in auxin responses SlIAA9. Ueta et al. used CRISPR/Cas9 to efficiently engineer parthenocarpy into two commercial tomato varieties. […]
Plant parasitic nematodes, including root-knot nematodes and cyst nematodes, cause extensive damage and loss to many crops. Nematodes elicit a pathogen-triggered immunity (PTI) defense response, but the molecular basis for this response has not been previously characterized. Mendy et al. identified a leucine-rich repeat receptor-like kinase NILR1 that recognizes an as yet unknown nematode protein […]
In a screen for chemicals that regulate strigolactone (SL) levels in rice, Ito et al. found that gibberellins suppress SL biosynthesis. This effect depends on the gibberellin signaling module, and involve a decrease in expression level of SL-biosynthetic genes. Furthermore, GA treated rice exuded less SL into the soil, and Striga seed germination frequency was […]
Strigolactones are both hormones that control shoot architecture and signals that promote interactions with arbuscular mycorrhizal fungi and promote germination of detrimental parasitic weeds such as Striga asiatica and Striga hermonthica. Gobena et al. mapped and cloned a sorghum gene, LOW GERMINATION STIMULANT 1 (LGS1), previously identified as conferring less stimulation of germination in Striga. […]
Phosphate is a limiting nutrient in soil and not very mobile, so roots respond strongly to low Pi soils by the cessation of elongation of the primary root with accompanying stimulation of lateral root and root hair production. Previously, the accumulation of iron (Fe3+) in the apoplast of root meristem cells with accompanying callose deposition […]
Sugar is a signal as well as an energy source, and plants monitor sugar levels to maintain an appropriate growth rate and rate of photosynthesis. A new study by Kelly et al. points to a role for sugars in the expression and activity of plasma-membrane (PIP) aquaporins. Aquaporins (AQP) are membrane channels for water and […]
Border cells form at the root tip and are shed during growth, protecting the sensitive root apex from damage as it pushes through the soil. Mravec et al. investigated the cell wall chemistry, carbohydrate distributioion and expression of cell-wall modifying genes to determine the mechanism by which border cells separate from their neighboring cells. Their […]
Review: Rubisco activases: AAA+ chaperones adapted to enzyme repair Rubisco, the fundamental enzyme required for photosynthetic carbon fixation, is susceptible to inactivation by the inhibitory binding of various metabolites. Rubisco activases (Rca’s) are enzymes that remodel Rubisco and facilitate the elimination of the inhibitor. All photosynthetic organisms have Rubisco activases that share a AAA+ domain. […]