Expression of auxin synthesis gene tms1 under control of tuber‐specific promoter enhances potato tuberization in vitro

Abstract

Phytohormones, auxins in particular, play an important role in plant development and productivity. Earlier data showed positive impact of exogenous auxin on potato (Solanum tuberosum L.) tuberization. The aim of this study was to generate potato plants with increased auxin level predominantly in tubers. To this end, a pBinB33-tms1 vector was constructed harboring the Agrobacterium auxin biosynthesis gene tms1 fused to tuber-specific promoter of the class I patatin gene (B33-promoter) of potato. Among numerous independently generated B33:tms1 lines, those without visible differences from control were selected for detailed studies. In the majority of transgenic lines, tms1 gene transcription was detected, mostly in tubers rather than in shoots. Indoleacetic acid (IAA) content in tubers and the auxin tuber-to-shoot ratio were increased in tms1-expressing transformants. The organ-specific increase in auxin synthesis in B33:tms1-transformants accelerated and intensified the process of tuber formation, reduced the dose of carbohydrate supply required for in vitro tuberization, and decreased the photoperiodic dependence of tuber initiation. Overall, a positive correlation was observed between tms1 expression, IAA content in tubers, and stimulation of tuber formation. The revealed properties of B33:tms1 transformants imply an important role for auxin in potato tuberization and offer prospects to magnify potato productivity by a moderate organ-specific enhancement of auxin content.Keywords: Auxin; gene expression; Solanum tuberosum; tms1; transgenic potato; tuberization; tuber yield Citation: Kolachevskaya OO, Alekseeva VV, Sergeeva LI, Rukavtsova EB, Getman IA, Vreugdenhil D, Buryanov YI, Romanov GA (2015) Expression of auxin synthesis gene tms1 under control of tuberspecific promoter enhances potato tuberization in vitro.

Genome-wide survey and expression analysis of the amino acid transporter superfamily in potato ( Solanum tuberosum L.)

“…In rice, the OsAUX subfamily genes were mainly expressed in 7-d-old young roots (Zhao et al, 2012). In potato, auxin affects tuber initiation and tuberization (Roumeliotis et al, 2013;Kolachevskaya et al, 2015). In the present study, the StAUX subfamily genes had relatively high expressions in roots, petioles, and stolons, indicating that StAUXs might have functional roles in tuber formation in addition to similar functions in roots.…”

The Multiple Signals That Control Tuber Formation

“…The activity of GA20 OXIDASE1 (GA20OX1), a biosynthetic enzyme, is repressed during tuberization, whereas GA2OX1, a catabolic enzyme, is strongly induced during the early stages of tuber formation (Kloosterman et al, 2007). Because of their importance in cell growth, both cytokinin and auxin metabolism also have been implicated as causal processes in tuberization (Roumeliotis et al, 2012(Roumeliotis et al, , 2013bEviatarRibak et al, 2013;Kolachevskaya et al, 2015;Gao et al, 2016). Numerous reports of the enhanced activity of a particular hormone or receptor have been consistently linked to tuber formation.…”

Multiple Mobile mRNA Signals Regulate Tuber Development in Potato

“…This results in a globular-shaped organ, the tuber, that will eventually become more ovate in shape. Other hormones, such as auxin and cytokinins, also play important roles in controlling tuber formation [52,70,71]. Therefore, during the onset of tuberization, some cells in the stolon meristem become very active, whereas others in close proximity remain dormant.…”