[Paul Verslues] Low water potential and At14a-Like1 (AFL1) effects on endocytosis and actin filament organization.

In previous research, the Verslues laboratory found that AFL1 could protect plant growth during drought stress (Kumar et al., 2015 PNAS).  AFL1 is a plant specific protein of unknown function.  However, several clues from AFL1 sequence, its subcellular localization and proteins it interacts with, indicated that AFL1 could be involved in endocytosis or actin filament organization.  Both of these are fundamentally important cellular processes yet there is little information on how they are altered during drought acclimation.  In the present study, (Kumar et al., 2019, Plant Physiology) we found that overexpression of AFL1 could reverse the decline in bulk endocytosis that occurs during drought acclimation.  AFL1 also had substantial effect on actin filament organization during stress and partially colocalized with actin filaments (actin filaments were visualized using the fABD marker).  Further ongoing study of AFL1 in our laboratory promises to reveal mechanisms regulating endocytosis and actin filament organization during abiotic stress and also determine how these processes are involved in drought-related sensing and signaling.