Washington, August 30 (ANI): A team of scientists has silenced nine genes in a multicellular organism, which allowed them to discover molecular secrets of how certain plant tissues know which end is their growing tip, also referred to as polarized growth.The research was carried out by biologist Magdalena Bezanilla and colleagues at the University of Massachusetts Amherst, US.The biologists conducted these experiments in a moss, but the findings illuminate processes in two tissues-root hairs and pollen tubes-found in all seed plants. Root hairs are extremely fine individual cells that grow out of a plant’s root, greatly increasing its surface area to collect water, essential minerals and nutrients. Pollen tubes travel down the flower to fertilize the plant’s egg. Scientists have “a very limited knowledge” at the molecular level of how such cells determine the direction they’re growing, according to Bezanilla. Knowing how to interrupt pollen tube formation in plants such as corn and soybeans, for example, could help prevent genetically engineered crops from interbreeding with wild populations. Aiding root hair growth could boost drought-resistance to other economically important plants.The researchers focused on two proteins, actin and formin. Actin, in this case a kind of scaffold-builder needed to form root hairs and pollen tubes, forms filamentous polymers and is important for many cellular processes in species ranging from yeast to man. Formins, like actin, are found in many species and help to control actin polymer formation. Formins are critical for actin-based cellular processes.Tools in a biologist’s kit can now remove the function of specific proteins-usually one or two at a time-to silence a gene, but in this study, the researchers succeeded in silencing a remarkable nine genes at one time.Bezanilla and colleagues systematically silenced the many actin-regulating formins and determined which members of this protein family are needed to generate cells for proper tip growth.Other tools in the researchers’ kit are methods for re-introducing the silenced genes, either normal or modified versions.By “swapping parts” from closely related formin proteins and measuring tip growing activity for each combination, her research group eventually concluded that only one intact subclass of formins drives normal growth and controls how the plant recognizes its growing tip.”If you take away any part of the formin, tip growth stops,” said Bezanilla.Interestingly, the researchers also discovered that this particular subclass of formins is the fastest yet known in any organism. (ANI)