Rhizobia secrete nodulation (Nod) factors, which set in motion the formation of nitrogen-fixing root nodules on legume host plants. Nod factors induce several cellular responses in root hair cells within minutes, but also are essential for the formation of infection threads by which rhizobia enter the root. Based on studies using bacterial mutants, a two-receptor model was proposed, a signaling...

Rhizobia preferentially enter legume root hairs via infection threads, after which root hairs undergo tip swelling, branching, and curling. However, the mechanisms underlying such root hair deformation are poorly understood. Here, we showed that a type II small GTPase, ROP10, of Medicago truncatula is localized at the plasma membrane (PM) of root hair tips to regulate root hair tip growth. Over...

Process monitoring allows for unique opportunities to capture information at intermediate layers during fabrication part qualification, but also improve process robustness by identifying issues before yield or quality is reduced. An industrial-grade laser profilometer has been integrated the first time in a commercial polymer sintering machine and used monitor powder bed potentially qualify par...

3296-Pos Board B451 Assembly and Architecture of Gram-Positive and -Negative Cell Walls James C. Gumbart1, Morgan Beeby2, Grant Jensen3, Benoit Roux4. Georgia Tech, Atlanta, GA, USA, Imperial College, London, United Kingdom, Caltech, Pasadena, CA, USA, U. Chicago, Chicago, IL, USA. The cell wall, a porous mesh-like structure, provides shape and physical protection for bacteria. At the atomic le...

Underwater exploration or inspection requires suitable robotic systems capable of maneuvering, manipulating objects, and operating untethered in complex environmental conditions. Traditional robots have been used to perform many tasks underwater. However, they limited degrees freedom, manipulation capabilities, portability, disruptive interactions with aquatic life. Research soft robotics seeks...

A critical step in establishing a successful nitrogen-fixing symbiosis between rhizobia and legume plants is the entrapment of the bacteria between root hair cell walls, usually in characteristic 180 degrees to 360 degrees curls, shepherd's crooks, which are formed by the host's root hairs. Purified bacterial signal molecules, the nodulation factors (NFs), which are lipochitooligosaccharides, i...

Tomato yellow leaf curl China virus (TYLCCNV) is a monopartite begomovirus associated with different betasatellites. In this study, we investigate two different isolates of Tomato yellow leaf curl China betasatellite (TYLCCNB) to determine what features of the viral genome are required for induction of characteristic phenotypic differences between closely-related betasatellite. When co-agroinoc...

Directional root expansion is governed by nutrient gradients, positive gravitropism and hydrotropism, negative phototropism and thigmotropism, as well as endogenous oscillations in the growth trajectory (circumnutation). Null mutations in phylogenetically related Arabidopsis thaliana genes MILDEW RESISTANCE LOCUS O 4 (MLO4) and MLO11, encoding heptahelical, plasma membrane-localized proteins pr...

We study the propagation of electromagnetic waves in one-dimensional chirped periodic structures composed of alternating layers of negative-index or left-handed metamaterial and conventional dielectric, under the condition of the zero average refractive index. We consider the case when the periodic structure has a linear chirp, and the chirp is introduced by varying linearly the thickness of th...

To meet Sean Carroll on his home turf in the early spring of Wisconsin is like encountering a bear cuddled up in his lair, waiting out the cold winter. I burrowed into the softly lit cave of small offices, with stalactites of yellow post-its dripping from every imaginable surface. Tiptoeing over misaligned stacks of books and reprints, I had to resist the urge to pick up one of the worn works, ...