*2.2. Bee Pollen Collection*

BP-Am was collected in April 2021 (during the *A. mono* Maxim. flower season) from an apiary located at the *A. mono* Maxim. planting base in Jilin Province, China. BP-Am samples were confirmed through palynological analysis [17] to have about 82% *A. mono* Maxim. pollen grains. BP-Pa was collected in May 2021 (during the *P. amurense* Rupr. flowering season) from an apiary located at the *P. amurense* Rupr. planting base in Jilin Province, China. BP-Pa samples were confirmed to have about 86% *P. amurense* Rupr. pollen grains. Our samples met the requirements for classification as monofloral bee pollen (>80%) [18]. Bee pollen samples were ground and lyophilized into powder, sterilized by irradiation at 7 kGy, then stored at −80 ◦C prior to further study.
