Analysis of five novel putative constitutive gene promoters in transgenic rice plants

Abstract

Novel constitutive gene promoters are essential components of crop biotechnology. Our analysis of five such promoters, APX, SCP1, PGD1, R1G1B, and EIF5, in transgenic rice plants is reported here. The five promoter regions were linked to the gfp reporter gene and transformed into rice. Using fluorescent microscopy and q-RT-PCR, promoter activities were analysed in comparison with OsCc1, Act1, and ZmUbi1, previously characterized as strong constitutive promoters. The APX and PGD1 promoters direct high levels of gene expression in all tissues and stages, producing GFP at levels of up to 1.3% of the total soluble protein. PGD1 is particularly active in flowers and mature roots. The R1G1B is active in the whole grain including the embryo, endosperm, and aleurone layer, and thus represents a constitutive promoter with activity in whole seeds that has not been described previously. The ZmUbi1 and R1G1B promoters are markedly less active in young roots and mature leaves whilst the APX, PGD1, OsCc1, and Act1 promoters are highly active in both vegetative and reproductive tissues. Overall, our results demonstrate that APX, PGD1, and R1G1B are novel gene promoters that are highly active at all stages of plant growth with distinct levels of activity.

Sugarcane (NCo310) Transient Transformation Using uidA Reporter Gene

“…Although the CaMV 35S promoter has been shown to be active in most tissues of several plant species (26), in this research it was found to be the weakest of the promoters tested in sugarcane. While differences in transient gene expression level were observed among the monocot promoters, the highest activity was obtained with the Act1 promoter, which is in agreement with previous reports on the Act1-D promoter activity in other monocots such as date palm (16) and rice (27). In conclusion, the histochemical staining results indicated that the rice Act1 promoter is preferred for stable expression of foreign genes in sugarcane callus.…”

Cis-regulatory elements used to control gene expression in plants

“…It has to be emphasized that promoters isolated from dicotyledonous plants are more efficient while used in dicots. The same rule applies for promoters isolated from monocots (Park et al 2010). Odell et al (1985) analyzed the sequence of constitutive promoter CaMV 35S , isolated from Cauliflower mosaic virus.…”

“…Alike constitutive promoters, those obtained from monocots may not be equally active in dicots (and vice versa). Occasionally, application of promoter considered as specific may result in non-specific heterologous gene expression (Park et al 2010). For example, wheat transformation with glutenin promoter LMWG1D1 led to the efficient expression within the endosperm.…”

“…ZmUbi1 promoter ensures high expression levels, particularly in young leaves and roots. Concurrently with plant maturation, production of the protein of interest decreases (Christensen et al 1992;Park et al 2010;Shepherd et al 2014). Inducing heat-stress on the plant may increase ZmUbi1 efficiency.…”

Transformação genética de laranjas 'Pera' e 'Natal' (Citrus sinensis L. Osbeck) com o gene atacina A (attA), dirigido por promotores preferencialmente expressos no floema, para resistência a Candidatus Liberibacter spp.

“…Em plantas transgênicas de citros, o promotor constitutivo 35S, oriundo do vírus do mosaico da couve-flor (CaMV) é o mais utilizado nas construções gênicas (FAGOAGA et al, 2001;YANG et al, 2011;MUNIZ et al, 2012). Park et al (2010) mostraram ainda que, este promotor regula a expressão do transgene em níveis elevados.…”