Cysteine-rich group III Gγ proteins are multiple, variable length heterotrimeric G-protein complex subunits that are associated with contrasting regulatory roles in seed yield and abiotic stress responses of vascular plants. Of these, Arabidopsis AGG3 has been widely studied and known to mediate ABA-dependent stress responses and regulate organ size. In this issue, Torres Rodriguez et al. (on pp. 1243-1256) investigated additional functions of AGG3 by its overexpression in the monocot model Setaria viridis and found that resultant plants were more tolerant to heat stress applied during anthesis, due to increased stress-responsive gene expression and improved photosynthetic efficiency. This finding further confirms the role of AGG3 as a general positive regulator of plant responses to unfavourable environmental conditions.
The cover image shows a nine-week-old wild-type S. viridis plant (left) and two independent overexpression lines (middle and right) showing improved growth three-weeks after heat stress treatment. Photo credit: Maria Daniela Torres Rodriguez (Donald Danforth Plant Science Center, USA)