A tomato plastidic ATP/ADP transporter gene SlAATP increases starch content in transgenic Arabidopsis

Abstract

A plastidic ATP/ADP transporter (AATP) is responsible for importing ATP from the cytosol into plastids. Increasing the ATP supply is a potential way to facilitate anabolic synthesis in heterotrophic plastids of plants. In this work, a gene encoding the AATP protein, named , was successfully isolated from tomato. Expression of was induced by exogenous sucrose treatment in tomato. The coding region of was cloned into a binary vector under the control of 35S promoter and then transformed into to obtain transgenic plants. Constitutive expression of significantly increased the starch accumulation in the transgenic plants. Real-time quantitative PCR (qRT-PCR) analysis showed that constitutive expression of up-regulated the expression of phosphoglucomutase (), ADP-glucose pyrophosphorylase (), granule-bound starch synthase ( and ), soluble starch synthases (, , and ) and starch branching enzyme ( and ) genes involved in starch biosynthesis in the transgenic plants. Meanwhile, enzymatic analyses indicated that the major enzymes (AGPase, GBSS, SSS and SBE) involved in the starch biosynthesis exhibited higher activities in the transgenic plants compared to the wild-type (WT). These findings suggest that may improve starch content of by up-regulating the expression of the related genes and increasing the activities of the major enzymes invovled in starch biosynthesis. The manipulation of expression might be used for increasing starch accumulation of plants in the future.

StTrxF, a potato plastidic thioredoxin F-type protein gene, is involved in starch accumulation in transgenic Arabidopsis thaliana

“…SSS can be grouped into four types, SSS I, SSS II, SSS III and SSS IV [3][4][5]. A large body of evidence has illustrated that up-regulation of these genes could increase starch accumulation in plants [5,[18][19][20][21][31][32][33][34][35]. In our study, a significant increase of SSS activity was also observed in transgenic plants ( Figure 5).…”

“…Heterologous expression of SnRK1 from apple/sweet potato increases the starch content in transgenic tomato/tobacco plants [17,18]. Arabidopsis thaliana plants expressing AATP CONTACT Feibing Wang wangfeibing1986@163.com; wangfeibing@hyit.edu.cn from tomato/potato exhibit higher starch content [19,20]. Overexpression of IbAATP increases the starch and amylose content in transgenic sweet potato [21].…”

Constitutive Expression of <i>VvAATP</i> Increases Starch Content in Transgenic <i>Arabidopsis</i>

“…There a few reports that the AATP gene has been shown to be involved in starch accumulation in plants [17][18][19][20][21][22]. In this work, the VvAATP gene was isolated from grapevine.…”

“…The expression of VvAATP and starch biosynthesis related genes was analyzed by real-time quantitative PCR (qRT-PCR) as described by Wang et al [19]. The cDNA solution was used as templates for PCR amplification with gene specific primers ( Table 1).…”

“…Down-regulation of the potato StAATP decreased ADPG level by 25-70% and starch content by 19-51% in potato tubers [18]. Ectopic expression of SlAATP/StAATP/GmAATP from tomato/potato/soybean increased starch accumulation in the leaves of transgenic Arabidopsis plants [19][20][21]. Overexpression of IbAATP increased starch and amylose content in transgenic sweetpotato [22].…”