Project description:Plants establish mutualistic association with beneficial microbes while deploy the immune system to defend against pathogens. Little is known about the interplay between mutualism and immunity and about the mediator molecules. Here we show that plants respond differently to a bacterial volatile compound through integral modulation of the immune system and the phosphate starvation response (PSR) system, resulting in either mutualism or immunity. We found that the same exposure of a recognized plant growth-promoting rhizobacterium unexpectedly causes either beneficial or deleterious effects to plants. The beneficial-to-deleterious transition is dependent on plant nutrition of phosphorus (P) and is mediated by diacetyl (DA), a bacterial volatile compound. In P-sufficient plants, DA partially suppresses plant production of reactive oxygen species (ROS) and enhances symbiont colonization without compromising disease resistance. In P-deficient plants, DA elevates phytohormone-mediated immunity and consequently causes plant hypersensitivity to P deficiency. Therefore, DA affects the types of relation between plants and certain rhizobacteria in a way that depends on plant PSR system and phytohormone-mediated immunity.
Project description:Background: Honey bee is a major insect used for pollination of a number of commercial crops worldwide. However, the number of managed honey bee colonies has recently declined in several countries, and a number of possible causes are proposed. Although the use of honey bees for pollination can be considered as disruption of the habitat, its effects on honey bees' physiology have never been addressed. In Japan, more than 100 thousands colonies are annually used for pollination, and intriguingly 80% of them are used in greenhouses. Recently, honey bee colonies have often collapsed when they are introduced into greenhouses. Thus, to suppress colony collapses and maintain the number of worker bees in the colonies are essential for successful long-term pollination in greenhouses and recycling honey bee colonies.
Project description:Background: Honey bee is a major insect used for pollination of a number of commercial crops worldwide. However, the number of managed honey bee colonies has recently declined in several countries, and a number of possible causes are proposed. Although the use of honey bees for pollination can be considered as disruption of the habitat, its effects on honey bees' physiology have never been addressed. In Japan, more than 100 thousands colonies are annually used for pollination, and intriguingly 80% of them are used in greenhouses. Recently, honey bee colonies have often collapsed when they are introduced into greenhouses. Thus, to suppress colony collapses and maintain the number of worker bees in the colonies are essential for successful long-term pollination in greenhouses and recycling honey bee colonies. Honey bee hives were installed into strawberry and eggplant greenhouses, and then the gene expression profiles of the honey bees were examined at the different time periods. Total 16 samples with two replicates were analyzed.
