Endosidin20 is a broad-spectrum cellulose synthesis inhibitor with an herbicidal function

Abstract

One sentence summary: Cellulose biosynthesis inhibitor Endosidin20 has 13 synergistic effect with other cellulose synthesis inhibitors and has the potential 14 to be used as a spray herbicide.Abstract: Cellulose is an important component of plant cell wall that controls 33 anisotropic cell growth. Disruption of cellulose biosynthesis often leads to 34 inhibited cell growth. Endosidin20 (ES20) was recently identified as a cellulose 35 biosynthesis inhibitor (CBI) that targets the catalytic domain of Arabidopsis 36 cellulose synthase 6 (CESA6) to inhibit plant growth. Here, we characterized 37 the effects of ES20 on the growth of some other plant species and found that 38 ES20 is a broad-spectrum plant growth inhibitor. We compared the inhibitory 39 effects of ES20 and other CBIs on the growth of cesa6 plants that have 40 reduced sensitivity to ES20. We found that most of the cesa6 with reduced 41 sensitivity to ES20 show normal inhibited growth by other CBIs. ES20 also 42 shows synergistic inhibitory effect on plant growth when applied together with 43 other CBIs. We show ES20 has a different mode of action than tested CBIs 44 isoxaben, indaziflam and C17. ES20 not only inhibits Arabidopsis growth under 45 tissue culture condition, it inhibits plant growth under soil condition after direct 46 spraying. We demonstrate that plants carrying two missense mutations can 47 tolerate dual inhibition by ES20 and isoxaben. 48 49