GCTTCA as a novel motif for regulating mesocarp-specific expression of the oil palm (Elaeis guineensis Jacq.) stearoyl-ACP desaturase gene

Abstract

TAAAAT and a novel motif, GCTTCA found in the oil palm stearoyl-ACP desaturase (SAD1) promoter are involved in regulating mesocarp-specific expression. Two key fatty acid biosynthetic genes, stearoyl-ACP desaturase (SAD1), and acyl-carrier protein (ACP3) in Elaeis guineensis (oil palm) showed high level of expression during the period of oil synthesis in the mesocarp [12-19 weeks after anthesis (w.a.a.)] and kernel (12-15 w.a.a.). Both genes are expressed in spear leaves at much lower levels and the expression increased by 1.5-fold to 2.5-fold following treatments with ethylene and abscisic acid (ABA). Both SAD1 and ACP3 promoters contain phytohormone-responsive, light-responsive, abiotic factors/wounding-responsive, endosperm specificity and fruit maturation/ripening regulatory motifs. The activities of the full length and six 5' deletion fragments of the SAD1 promoter were analyzed in transiently transformed oil palm tissues by quantitative β-glucuronidase (GUS) fluorometric assay. The highest SAD1 promoter activity was observed in the mesocarp followed by kernel and the least in the leaves. GUS activity in the D3 deletion construct (- 486 to + 108) was the highest, while the D2 (- 535 to + 108) gave the lowest suggesting the presence of negative cis-acting regulatory element(s) in the deleted - 535 to - 486 (49 bp). It was found that the 49-bp region binds to the nuclear protein extract from mesocarp but not from leaves in electrophoretic mobility shift assay (EMSA). Further fine-tuned analysis of this 49-bp region using truncated DNA led to the identification of GCTTCA as a novel motif in the SAD1 promoter. Interestingly, another known fruit ripening-related motif, LECPLEACS2 (TAAAAT) was found to be required for effective binding of the novel motif to the mesocarp nuclear protein extract.

GmPTF1 modifies root architecture responses to phosphate starvation primarily through regulating GmEXPB2 expression in soybean

“…Many studies have also documented the involvement of cis-regulatory elements in a variety of regulatory networks adapted to mediate responses to fluctuating physiological and environmental conditions (Hanifiah et al, 2018;Kim et al, 2006;Rawat et al, 2005). In one relevant example, the R2R3 MYB TF PHR1 and its homologs appear to play central roles in P signaling and Pi homeostasis (Bari et al, 2006;Chiou and Lin, 2011;Liang et al, 2013;Sun et al, 2016;Xue et al, 2017).…”

“…Many studies have also documented the involvement of cis ‐regulatory elements in a variety of regulatory networks adapted to mediate responses to fluctuating physiological and environmental conditions (Hanifiah et al. , 2018; Kim et al. , 2006; Rawat et al.…”

GmPTF1 Modifies Root Architecture Responses to Phosphate Starvation in Soybean

“…Many studies have also documented the involvement of cis -regulatory elements in a variety of regulatory networks adapted to mediate responses to fluctuating physiological and environmental conditions (Hanifiah et al, 2018; Kim et al, 2006; Rawat et al, 2005). In one relevant example, the R2R3 MYB transcription factor PHR1 and its homologs appear to play central roles in P signaling and Pi homeostasis (Bari et al, 2006; Chiou and Lin, 2011; Liang et al, 2013; Sun et al, 2016; Xue et al, 2017).…”

Transcriptional Regulation of zma-MIR528a by Action of Nitrate and Auxin in Maize

“…After this, the protoplasts were harvested for further analysis. Transfection efficiency and normalization were assessed by absolute qPCR based on the number of copies of recombinant DNA successfully delivered into protoplasts after transfection, as previously reported [ 88 ].…”