Constitutive expression of StAATP, a potato plastidic ATP/ADP transporter gene, increases starch content in transgenic Arabidopsis

Abstract

The plastidic ATP/ADP transporter (AATP) imports adenosine triphosphate (ATP) from the cytosol into plastids, resulting in an increase in the ATP supply to facilitate the anabolic synthesis in heterotrophic plastids of dicotyledonous plants. In this study, a gene encoding the AATP protein, StAATP, was successfully isolated from potato and transformed into Arabidopsis. Constitutive expression of StAATP significantly increased the starch accumulation in the transgenic plants. Realtime quantitative polymerase chain reaction analysis showed that constitutive expression of StAATP up-regulated the expression of key genes involved in the starch biosynthesis pathway in the transgenic Arabidopsis plants: phosphoglucomutase (AtPGM), ADP-glucose pyrophosphorylase (AGPase) small subunit (AtAGPase-S1 and AtAGPase-S2), AGPase large subunit (AtAGPase-L1 and AtAGPase-L2), granule-bound starch synthase (AtGBSS I and AtGBSS II), soluble starch synthases (AtSSS I, AtSSS II, AtSSS III and AtSSS IV) and starch-branching enzyme (AtSBE I and AtSBE II) genes. Furthermore, the major enzymes involved in starch biosynthesis (AGPase, GBSS, SSS and SBE) exhibited higher catalytic activities in the transgenic plants compared to the wild type. These results indicate that StAATP may improve the starch content of Arabidopsis by up-regulating the expression of the related genes and increasing the activities of the major enzymes involved in starch biosynthesis. All these findings suggest that the StAATP gene may be applied 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].…”

Novel Loci for Kernel Hardness Appeared as a Response to Heat and Combined Heat-Drought Conditions in Wheat Harboring Aegilops tauschii Diversity

“…This marker encodes an ATP/ADP transporter gene. Wang et al [43] explained that ATP/ADP transporter genes increase the starch content in transgenic Arabidopsis. This could explain why the kernels of some genotypes became softer under stress conditions.…”

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.…”

“…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].…”