Function Analysis Of Diffreent Elements Of PGIP Promoters From Apple(Malus Domestic Borkh.)

qRT-PCR showed that expression levels of PGIP1 and PGIP2 in leaves from ’Qinguan’and ’Pacific Rose’ apples could be induced by Marssonina coronaria, salicylic acid and methyl jasmonate. In order to study the regions of PGIP promoters in response to Marssonina coronaria, salicylic acid and methyl jasmonate, the ’Qinguan’ and ’Pacific Rose’ apples PGIP1 and PGIP2 full-length gene promoters and 5’ deletion fragments fused to the GUS gene then were transfered to Arabidopsis thaliana. By detecting the activity of GUS gene expression levels in Arabidopsis leaves, the activity changes of ’Qinguan’ and ’Pacific rose’ apple PGIP1 and PGIP2 gene promoters induced by arabidopsis powdery mildew, salicylic acid and methyl jasmonate were analyzed, in order to select response elements of promoters under different treatments, study the function of apple PGIP gene promoters elements and discuss the disease-resistant expression mechanism of apple PGIP genes.1. PGIP promoters sequence element analysis of ’Qinguan’ and ’Pacific Rose’ apples dispayed that PGIP1 promoter had cis-acting regulatory element involved in the MeJA-responsiveness CGTCA-motif/TGACG-motif(-763~-759bp), while PGIP2 promoter had three cis-acting elements involved in salicylic acid responsiveness TC-rich repeats(Qinguan:-1594~-1585 bp,-1329~-1320 bp,-321~-312 bp. Pacific Rose:-1594~-1585 bp,-1332~-1323 bp,-321~-312bp) and a cis-acting element involved in defense and stress responsiveness(Qinguan:-1680~-1671bp; Pacific Rose:-1678~-1669bp).2. GUS expression levels measured in Arabidopsis leaves induced by powdery mildew showed that ’Qinguan’ apple PGIP2 full-length gene promoter(-2104~-1bp) and deletion fragments(-1705~-1bp) activities performed a significant increase, while deletion fragment(-421~-1bp) activity did not change, therefore,-1705~-421 bp were considered to be the critical region for ’Qinguan’ apple PGIP2 gene promoter in response to Arabidopsis powdery mildew. According to the ’Qinguan’ apple PGIP2 gene promoter sequence element analysis,responsive element might be the cis-acting element involved in defense and stress responsiveness TC-rich repeats(-1680~-1671bp). ’Qinguan’ Apple PGIP1 gene promoter,’Pacific Rose’ apple PGIP1 and PGIP2 gene promoter did not respond to Arabidopsispowdery mildew induction.3. Treated with salicylic acid, ’Qinguan’ apple PGIP2 full-length gene promoter(-2104~-1bp) activity significantly increased, while its deletion fragments activities had no changes; Induced by methyl jasmonate, ’Qinguan’ apple PGIP2 full-length gene promoter and its deletion fragments had no response. According to the ’Qinguan’ apple PGIP2 gene promoter sequence element analysis, the results verified the function of cis-acting element involved in salicylic acid(-1594~-1585 bp,-1329~-1320 bp,-321~-312bp) and inexistence of cis-acting regulatory element involved in the MeJA-responsiveness TCA-element, but the salicylic acid response region could not be located; GUS expression levels measured in Arabidopsis leaves displayed that ’Qinguan’ apple PGIP1 gene promoter, ’Pacific Rose’ apple PGIP1 and PGIP2 gene promoter did not respond to salicylic acid and methyl jasmonate.