Transgenic tobacco (Nicotiana tabacum) SR1 plants expressing the Agrobacterium tumefaciens nopaline transferred DNA iaaH gene were transformed with a 35S-iaaM construct. The transformants displayed several morphological aberrations, such as adventitious root formation on stem and leaves, dwarfism, epinastic leaf growth, increased apical dominance, an overall retardation in development. In addition, xylem lignification was higher than wild type. Free conjugated indoleacetic acid (IAA) levels...

Tobacco leaf was used to investigate the mechanism of action auxin-binding protein 1 (ABP1). The distributions free auxin, ABP1, percentage nuclei in G2 and amount auxin-inducible growth were each determined control tobacco leaves over-expressing Arabidopsis ABP1. These parameters compared with leaves, measured both spatially temporally throughout entire expansion phase. Within a defined window development, juvenile cells that inducibly expressed ABP1 prematurely advanced ABP1-induced...

Abstract Transgenic potato (Solanum tuberosum cv Désirée) plants overexpressing a soybean (Glycine max) type 1 sterol methyltransferase (GmSMT1) cDNA were generated and used to study biosynthesis in relation the production of toxic glycoalkaloids. displayed an increased total level both leaves tubers, mainly due levels 24-ethyl sterols isofucosterol sitosterol. The higher was increases free esterified sterols. However, cholesterol, nonalkylated sterol, decreased. Associated with this...

A key regulator of cambial growth is the plant hormone indoleacetic acid (IAA). Here we report on altered wood characteristics and patterns in transgenic hybrid aspen (Populus tremula L. x Populus tremuloides Michx.) expressing Agrobacterium tumefaciens T-DNA IAA-biosynthetic iaaM iaaH genes. Eighteen lines simultaneously both genes were regenerated. Of these, four lines, verified to be by northern blot analysis, selected raised under controlled conditions. All affected their patterns,...

Potato tubers naturally contain a number of defense substances, some which are major concern for food safety. Among these substances the glycoalkaloids and calystegines. We have here analyzed levels (α-chaconine α-solanine) calystegines (A3, B2, B4) in potato subjected to mechanical wounding, light exposure, or elevated temperature: stress treatments that known anticipated induce glycoalkaloid levels. Basal varied between cultivars. Wounding but not heat, increased tuber levels, relative...

Current hypotheses concerning the role of polar auxin transport in embryo development are entirely based on studies angiosperms, while little is known about how regulates pattern formation gymnosperms. In this study, different developmental stages somatic embryos Norway spruce (Picea abies) were treated with inhibitor 1-N-naphtylphthalamic acid (NPA). Effects treatments content, differentiation and programmed cell death (PCD) analysed. During early development, NPA-treatment led to increased...

During embryo development in most gymnosperms, the establishment of shoot apical meristem (SAM) occurs concomitantly with formation a crown cotyledons surrounding SAM. It has previously been shown that differentiation somatic embryos Picea abies is dependent on polar auxin transport (PAT). In angiosperm model plant, Arabidopsis thaliana, cotyledonary boundaries and embryonal SAM PAT expression CUP-SHAPED COTYLEDON (CUC) genes, which belong to large NAC gene family. The aim this study was...

Summary Transgenic tobacco lines simultaneously expressing the Agrobacterium iaaM , iaaH and ipt genes, obtained by crossing with were used to study in planta interactions between auxin cytokinins. All phenotypic traits of respective parental characteristic cytokinin overproduction present cross. Indole‐3‐acetic acid (IAA) combined zeatin riboside (ZR) riboside‐5′‐monophosphate (ZRMP) contents analysed mass spectrometry young, developing leaves from cross, wild type. Unexpectedly, hormone...

The Agrobacterium tumefaciens T-DNA gene iaaM was introduced by leaf-disc transformation into transgenic tobacco (Nicotiana tabacum) plants expressing the iaaH gene. Regenerated calli were screened for presence of indole-3-acetamide (IAM), gas chromatography-multiple ion monitoring-mass spectrometry, and IAM-containing further analyzed free conjugated indoleacetic acid (IAA). It found that on average contained twice as much IAA three times more than from wild-type plants. About 40%...

Auxins constitute a small class of plant hormones having profound effects on development. Among the fastest cellular responses to auxin addition is an alteration gene expression, and abundance several mRNA species has been shown increase, or decrease, within minutes hours after treatment. The regulation this process appears, at least partly, be transcriptional level. Using differential screening approaches, number auxin‐regulated cDNAs genes have isolated, mainly from elongating tissues...

Transgenic plants overproducing indole-3-acetic acid (IAA) from expression of the Agrobacterium tumefaciens T-DNA IAA biosynthesis genes were used to study conjugation IAA. At 11-node stage, free IAA, as well ester- and amide-conjugated was analyzed in wild-type tobacco SR1 transgenic denoted 35S-iaaM/iaaH (line C) 35S-iaaM x 35S-iaaH X). The contained increased levels both conjugated main increase conjugates occurred amide conjugates. Two identified by fritfast atom bombardment liquid...

Establishment of the shoot apical meristem (SAM) in Arabidopsis embryos requires KNOXI transcription factor SHOOT MERISTEMLESS. In Norway spruce (Picea abies), four family members (HBK1, HBK2, HBK3 and HBK4) have been identified, but a corresponding role SAM development has not demonstrated. As first step to differentiate between functions HBK genes, we here analyzed their expression profiles during process somatic embryo development. This was made both under normal conditions reduced...

Steroidal glycoalkaloids (SGA) are sterol-derived neurotoxic defence substances present in several members of the Solanaceae. In potato (Solanum tuberosum), high SGA levels may render tubers harmful for consumption. Tuber depend on genetic factors, and can increase as a response to certain stresses environmental conditions. To identify genes underlying cultivar variation tuber levels, we investigated two cultivars differing their accumulation during wounding or light exposure; known...

Early auxin-regulated tobacco cDNAs, belonging to the Aux/IAA gene family have been isolated by screening of a cDNA library prepared from auxin-treated suspension-grown etiolated seedlings Nicotiana tabacum. The probes used were either RT-PCR fragments or an insert resulting mRNA differential display selection. All them possessed structural features which characterize products. auxin response three distinct Nt-iaa subclasses has characterized in terms kinetics, dose-response and specificity...

Abstract To explore mechanisms in plant sterol homeostasis, we have here increased the turnover of sterols Arabidopsis (Arabidopsis thaliana) and potato (Solanum tuberosum) plants by overexpressing four mouse cDNA encoding cholesterol hydroxylases (CHs), hydroxylating at C-7, C-24, C-25, or C-27 positions. Compared to wild type, types transformant showed varying degrees phenotypic alteration, strongest one being CH25 lines, which were dark-green dwarfs resembling brassinosteroid-related...