Beta galactosidase assays

Yeast transformation and beta-galactosidase assays were performed following the manufacturer’s instructions (Clontech). Full-length cDNAs for WUS, HAM1, HAM2, HAM3, and HAM4 were cloned into pENTR/D/TOPOor pCR8 (Invitrogen), and then WUS cDNA was Gateway cloned to pDEST32, and HAM1, HAM2, HAM3, and HAM4 cDNAs were Gateway cloned into pDEST22 using standard LR reactions (Invitrogen). All of the deletion derivatives for WUS or HAM1 were generated through overlapping PCR with the primers listed in methods, cloned into pENTR/D-TOPO or pCR8, and cloned into pDEST32 or pDEST22 through LR recombination (Invitrogen). All clones were sequenced to confirm they were in-frame and the corresponding deletions before being transformed into yeast. The bait and prey vectors were transformed into yeast strain MaV203, and three single transformed colonies per genotype were used as triplicate for the LacZ liquid assay in 96 Deep well plates (Thermo) and OD reading was recorded in 96-well plate reader (Tecan). The LacZ activity was calculated as (OD420×1000)/(OD600 × cell volume in μl × assay time in minutes) following the yeast two hybrid handbook (Clontech), including a standard error from three biological replicates.