Analysis of transcriptional regulation and tissue-specific expression of Avicennia marina Plasma Membrane Protein 3 suggests it contributes to Na+ transport and homoeostasis in A. marina. (July 2015)

• Record Type: Journal Article
• Authors: Chidambaram, Rajalakshmi; Venkataraman, Gayatri; Parida, Ajay
• Is Part Of: Plant science. Volume 236(2015:Jul.)
• Page Start: 89
• Page End: 102
• Publication Date: 2015-07
• Subjects: PMP3 plasma membrane protein -- AmPMP3 promoter AmPMP3prom -- GFP green fluorescent protein -- GUS β-glucouronidase -- CAMV35S cauliflower mosaic virus 35S promoter -- ABRE abscisic acid regulatory element -- DRE Drought Regulatory Element -- HKT sodium transporter -- T2 T2 generation plants -- NT non-transgenic -- VEC vector control; Deletion analysis -- Enhancer -- Mangrove -- PMP3 -- Salinity -- Transgenic tobacco; Botany -- Periodicals; Botanique -- Périodiques; 580
• DOI: 10.1016/j.plantsci.2015.03.013
• Languages: English
• ISSNs: 0168-9452

Abstract

Highlights: AmPMP3prom shows distal enhancer and stem specific negative regulatory regions. Distal enhancer in AmPMP3prom confers salinity induced GUS activity. Pronounced salinity inducible guard cell and vascular GFP:AmPMP3 expression. AmPMP3 contributes to salinity-induced Na + homoeostasis in A. marina . Abstract: Plasma membrane proteins (PMP3) play a role in cation homoeostasis. The 5′ flanking sequence of stress inducible, Avicennia marina PMP3 ( AmPMP3prom ) was transcriptionally fused to (a) GUS or (b) GFP-AmPMP3 and analyzed in transgenic tobacco. Tissue-histochemical GUS and GFP:AmPMP3 localization are co-incident under basal and stress conditions. AmPMP3prom directed GUS activity is highest in roots. Basal transcription is conferred by a 388 bp segment upstream of the translation start site. A 463 bp distal enhancer in the AmPMP3prom confers enhanced expression under salinity in all tissues and also responds to increases in salinity. The effect of a central, stem-specific negative regulatory region is suppressed by the distal enhancer. The A. marina rhizosphere encounters dynamic changes in salinity at the inter-tidal interface. The complex, tissue-specific transcriptional responsiveness of AmPMP3 to salinity appears to have evolved in response to these changes. Under salinity, guard cell and phloem-specific expression of GFP:AmPMP3 is highly enhanced. Mesophyll, trichomes, bundle sheath, parenchymatous cortex and xylem parenchyma also show GFP:AmPMP3 expression. Cis-elements conferring stress, root and vascular-specific expression are enriched in the AmPMP3 promoter. Pronounced vascular-specific AmPMP3 expression suggests a role in salinity induced Na + transport, storage, and secretion in A. marina .