RNA extraction and analysis. Total RNA was extracted from the shoots and leaf
blades by using a NucleoSpin RNA II (Macherey-Nagel). Genomic DNA was
removed using TURBO DNA-freeTM Kit. RT-PCR assay was conducted using onestep
RT-PCR kit (Quick Master Mix; TOYOBO) according to the manufacturer’s
instructions. PCR analysis consisted of 40 cycles by using primers shown in
Supplementary Table S2 online. RNA extraction and RT-PCR were repeated three times for each sample. To isolate the cDNA of BPH26 from ADR52, ASD7, and
Norin-PL4, RACE-PCR was performed using a SMARTer RACE cDNA
Amplification Kit (Clontech). RACE-PCR products were cloned and sequenced.