Gressel, J. | bioRxiv Science

bioRxiv2024

Generation of biobased, biodegradable non-woven straw mats for multiple environmentally friendly uses

Two billion tons of grains straws are produced annually, most of which has a negative ecological value. A small proportion is fed to ruminants as a low calory roughage. Grain straws had been burnt to prevent pathogen spores from over-wintering, now requiring greater fungicide use if left on soil surface, or more fertilizer use when the straw is plowed under and then binds nutrients. Lignin from paper making had been dumped, but is now finding limited uses, including as a glue in plywood manufacture. We propose to find the right ratio of lignin and other biodegradable adhesives coated on straw along with ascertaining the optimal pressures and temperatures for binding the adhesives and them cross-link straw fibers into mats. These slowly-biodegradable mats can be as: 1. Filters surrounding fish pens, binding pollutants from fish excrements, which are metabolized along with the straw by periphyton into material edible by fish as well as zooplankton eaten by fish. These filter mats may also prevent the movement of parasites into or out of the pens; 2. Mats used for erosion control on bare slopes until vegetated; 3. As insulation material in construction, where the carbon will be sequestered for decades; 4. As a compostable packaging material replacing polystyrene and bubble wrap; 5. Weed-preventing soil covering in organic and conventional agriculture. Such mats can be doped with ammonium and potassium as well as calcium and magnesium to be slowly released as fertilizer. Thus, by combining a negative environmental value waste materials with an adhesive we can generate mats that have very positive environmental benefits.

bioengineering↗

bioRxiv2024

Pesticide chemical leads inhibiting protein-protein interactions

Pesticides, especially herbicides, have revolutionized agriculture by providing energy-efficient solutions for pest control that replaces labor-intensive cultivation methods. However, the widespread evolution of pesticide resistance poses a significant challenge to current agriculture. Most pesticides function by binding to specific pockets on target enzymes, enabling a single mutation to confer resistance. An alternative approach is the disruption of protein-protein interactions (PPI), thus for resistance to occur, it requires complementary mutations on both interacting partners. Despite extensive efforts, no herbicides with new modes of action have been commercialized for decades. Thus, we focused on the discovery and design of small molecule inhibitors that target the interface of the PPI complex of O-acetylserine sulfhydrylase (OASS) and serine acetyltransferase (SAT), key plant enzymes involved in the biosynthesis of the essential amino acid cysteine. Using in silico filtering techniques on a virtual library of 30 million small molecules, we identified initial hits capable of binding OASS and interfering with its interaction with a peptide derived from SAT. Subsequently, we conducted chemical optimizations to evaluate biophysical enzyme disruption, followed by cellular and in-planta activity in plants. These new compounds described herein can serve as promising starting points for further optimization as herbicides acting on a new mode of action.

biochemistry↗