Infection of Alfalfa Cotyledons by an Incompatible but Not a Compatible Species of Induces Formation of Paramural Bodies and Secretion of EVs.

Hemibiotrophic fungi in the genus employ a biotrophic phase to invade host epidermal cells followed by a necrotrophic phase to spread through neighboring mesophyll and epidermal cells. We used serial block face-scanning electron microscopy (SBF-SEM) to compare subcellular changes that occur in (alfalfa) cotyledons during infection by (compatible on ) and (incompatible on ). Three-dimensional reconstruction of serial images revealed that alfalfa epidermal cells infected with undergo massive cytological changes during the first 60 h following inoculation to accommodate extensive intracellular hyphal growth.

Three-Dimensional Ultrastructure of Cotyledons Infected with .

We used serial block-face scanning electron microscopy (SBF-SEM) to study the host-pathogen interface between cotyledons and the hemibiotrophic fungus . By combining high-pressure freezing and freeze-substitution with SBF-SEM, followed by segmentation and reconstruction of the imaging volume using the freely accessible software IMOD, we created 3D models of the series of cytological events that occur during the susceptible interaction. We found that the host cell membranes underwent massive expansion to accommodate the rapidly growing intracellular hypha.

Improved Yield and Photosynthate Partitioning in AVP1 Expressing Wheat () Plants.

A fundamental factor to improve crop productivity involves the optimization of reduced carbon translocation from source to sink tissues. Here, we present data consistent with the positive effect that the expression of the H-PPase () has on reduced carbon partitioning and yield increases in wheat. Immunohistochemical localization of H-PPases (TaVP) in spring wheat Bobwhite L.

Assessing Long-Distance Carbon Partitioning from Photosynthetic Source Leaves to Heterotrophic Sink Organs with Photoassimilated [C]CO.

Phloem loading and long-distance transport of photoassimilate from source leaves to sink organs are essential physiological processes that contribute to plant growth and yield. At a minimum, three steps are involved: phloem loading in source organs, transport along the phloem path, and phloem unloading in sink organs. Each of these can have variable rates contingent on the physiological state of the plant, and thereby influence the overall transport rate.

Alternate Modes of Photosynthate Transport in the Alternating Generations of .

has emerged as a model moss system to investigate the evolution of various plant characters in early land plant lineages. Yet, there is merely a disparate body of ultrastructural and physiological evidence from other mosses to draw inferences about the modes of photosynthate transport in the alternating generations of . We performed a series of ultrastructural, fluorescent tracing, physiological, and immunohistochemical experiments to elucidate a coherent model of photosynthate transport in this moss.

Apoplasmic loading in the rice phloem supported by the presence of sucrose synthase and plasma membrane-localized proton pyrophosphatase.

Background And Aims: Although Oryza sativa (rice) is one of the most important cereal crops, the mechanism by which sucrose, the major photosynthate, is loaded into its phloem is still a matter of debate. Current opinion holds that the phloem loading pathway in rice could involve either a symplasmic or an apoplasmic route. It was hypothesized, on the basis of a complementary body of evidence from arabidopsis, which is an apoplasmic loader, that the membrane specificity of proton pyrophosphatases (H(+)-PPases; OVPs) in the sieve element-companion cell (SE-CC) complexes of rice source leaves would support the existence of either of the aforementioned phloem loading mechanisms.