Fig. 4. The LRR-RK HSL1 can mimic HAESA, acting as a positive regulator of floral abscission.

a HSL1, which is not typically expressed in abscission zone (AZ), can perceive IDA in vivo and replace the receptor HAESA in floral shedding. Abscission complementation assays of hae hsl2 double mutant expressing the receptor HSL1 under the HAESA promoter. As control, the HAESA receptor was expressed under the HSL1 promoter. A minimum of two independent lines were analyzed for floral abscission phenotype. Wilt type Col-0, and hae hsl2 and hsl1 mutants were also phenotyped alongside. b Localization of HSL1 in AZ under the expression of the HAESA promoter. Confocal images of AZ of pHAESA::HSL1::mGFP lines. Scale bar = 100 μm.