scholarly journals Surface growth at the reproductive shoot apex of Arabidopsis thaliana pin-formed 1 and wild type

2004 ◽  
Vol 55 (399) ◽  
pp. 1021-1032 ◽  
Author(s):  
D. Kwiatkowska
Keyword(s):  
Arabidopsis Thaliana ◽  
Shoot Apex ◽  
Surface Growth ◽  
Wild Type ◽  
Reproductive Shoot

Reduction of root flavonoid level and its potential involvement in lateral root emergence in Arabidopsis thaliana grown under low phosphate supply

2009 ◽  
Vol 36 (6) ◽  
pp. 564 ◽  
Author(s):  
Huixia Yang ◽  
Hong Liu ◽  
Gang Li ◽  
Juanjuan Feng ◽  
Huanju Qin ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Potential Function ◽  
Shoot Apex ◽  
Lateral Root ◽  
Higher Plants ◽  
Wild Type ◽  
Knockout Mutant ◽  
Phosphate Supply ◽  
Pi Deficiency ◽  
Flavonoid Accumulation

Although it is well known that phosphate (Pi) deficiency affects flavonoid accumulation in higher plants, knowledge on the regulation and potential function of flavonoids in the plants grown with low Pi supply is lacking. In this work, we found that low Pi treatment caused significant reduction of root flavonoid (e.g. quercetin, kaempferol and their derivatives) levels in both Columbia (Col-0) and Landsberg erecta (Ler) ecotypes of Arabidopsis thaliana (L.) Heynh. Further investigations revealed that the dysfunction of PHR1, PHO1, PHO2 and NPC4 did not affect the decrease of root flavonoid level by low Pi treatment. In contrast, pldζ2, a knockout mutant of the Arabidopsis phospholipase Dζ2, exhibited defects in the reduction of root flavonoid level and lateral root (LR) emergence under low Pi conditions. When grown under low Pi supply, the transport of auxin from the shoot apex into the root, expression of the auxin responsive DR5::GUS marker and induction of the auxin responsive genes were all significantly less efficient in pldζ2 than in wild-type (WT) control. This is the first report on the reduction of root flavonoid level and its likely contribution to increased LR emergence in Arabidopsis under Pi deficiency conditions, which may facilitate the adaptation of plants to the growth environments with poor Pi availability.

scholarly journals FT-like proteins induce transposon silencing in the shoot apex during floral induction in rice

2015 ◽  
Vol 112 (8) ◽  
pp. E901-E910 ◽  
Author(s):  
Shojiro Tamaki ◽  
Hiroyuki Tsuji ◽  
Ayana Matsumoto ◽  
Akiko Fujita ◽  
Zenpei Shimatani ◽  
...  
Keyword(s):  
Shoot Apex ◽  
Higher Plants ◽  
Floral Induction ◽  
Heading Date ◽  
Sequencing Analysis ◽  
Wild Type ◽  
Flowering Locus T ◽  
Reproductive Shoot ◽  
Transposon Silencing ◽  
Crucial Information

Floral induction is a crucial developmental step in higher plants. Florigen, a mobile floral activator that is synthesized in the leaf and transported to the shoot apex, was recently identified as a protein encoded by FLOWERING LOCUS T (FT) and its orthologs; the rice florigen is Heading date 3a (Hd3a) protein. The 14-3-3 proteins mediate the interaction of Hd3a with the transcription factor OsFD1 to form a ternary structure called the florigen activation complex on the promoter of OsMADS15, a rice APETALA1 ortholog. However, crucial information, including the spatiotemporal overlap among FT-like proteins and the components of florigen activation complex and downstream genes, remains unclear. Here, we confirm that Hd3a coexists, in the same regions of the rice shoot apex, with the other components of the florigen activation complex and its transcriptional targets. Unexpectedly, however, RNA-sequencing analysis of shoot apex from wild-type and RNA-interference plants depleted of florigen activity revealed that 4,379 transposable elements (TEs; 58% of all classifiable rice TEs) were expressed collectively in the vegetative and reproductive shoot apex. Furthermore, in the reproductive shoot apex, 214 TEs were silenced by florigen. Our results suggest a link between floral induction and regulation of TEs.

scholarly journals Inhibition of cell expansion enhances cortical microtubule stability in the root apex of Arabidopsis thaliana

2021 ◽  
Vol 28 (1) ◽  
Author(s):  
Veronica Giourieva ◽  
Emmanuel Panteris
Keyword(s):  
Arabidopsis Thaliana ◽  
Cell Wall ◽  
Cell Expansion ◽  
Cortical Microtubule ◽  
Root Apex ◽  
Cellulose Synthase ◽  
Cellulose Biosynthesis ◽  
Cortical Microtubules ◽  
Wild Type ◽  
Microtubule Stability

Abstract Background Cortical microtubules regulate cell expansion by determining cellulose microfibril orientation in the root apex of Arabidopsis thaliana. While the regulation of cell wall properties by cortical microtubules is well studied, the data on the influence of cell wall to cortical microtubule organization and stability remain scarce. Studies on cellulose biosynthesis mutants revealed that cortical microtubules depend on Cellulose Synthase A (CESA) function and/or cell expansion. Furthermore, it has been reported that cortical microtubules in cellulose-deficient mutants are hypersensitive to oryzalin. In this work, the persistence of cortical microtubules against anti-microtubule treatment was thoroughly studied in the roots of several cesa mutants, namely thanatos, mre1, any1, prc1-1 and rsw1, and the Cellulose Synthase Interacting 1 protein (csi1) mutant pom2-4. In addition, various treatments with drugs affecting cell expansion were performed on wild-type roots. Whole mount tubulin immunolabeling was applied in the above roots and observations were performed by confocal microscopy. Results Cortical microtubules in all mutants showed statistically significant increased persistence against anti-microtubule drugs, compared to those of the wild-type. Furthermore, to examine if the enhanced stability of cortical microtubules was due to reduced cellulose biosynthesis or to suppression of cell expansion, treatments of wild-type roots with 2,6-dichlorobenzonitrile (DCB) and Congo red were performed. After these treatments, cortical microtubules appeared more resistant to oryzalin, than in the control. Conclusions According to these findings, it may be concluded that inhibition of cell expansion, irrespective of the cause, results in increased microtubule stability in A. thaliana root. In addition, cell expansion does not only rely on cortical microtubule orientation but also plays a regulatory role in microtubule dynamics, as well. Various hypotheses may explain the increased cortical microtubule stability under decreased cell expansion such as the role of cell wall sensors and the presence of less dynamic cortical microtubules.

Caffeoyl Shikimate Esterase (CSE) Is an Enzyme in the Lignin Biosynthetic Pathway in Arabidopsis

Science ◽  
2013 ◽  
Vol 341 (6150) ◽  
pp. 1103-1106 ◽  
Author(s):  
Ruben Vanholme ◽  
Igor Cesarino ◽  
Katarzyna Rataj ◽  
Yuguo Xiao ◽  
Lisa Sundin ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Cell Walls ◽  
Metabolite Profiling ◽  
Biosynthetic Pathway ◽  
Wild Type ◽  
Secondary Cell Walls ◽  
Phenolic Metabolite ◽  
In The Wild ◽  
Lignin Biosynthetic Pathway

Lignin is a major component of plant secondary cell walls. Here we describe caffeoyl shikimate esterase (CSE) as an enzyme central to the lignin biosynthetic pathway. Arabidopsis thaliana cse mutants deposit less lignin than do wild-type plants, and the remaining lignin is enriched in p-hydroxyphenyl units. Phenolic metabolite profiling identified accumulation of the lignin pathway intermediate caffeoyl shikimate in cse mutants as compared to caffeoyl shikimate levels in the wild type, suggesting caffeoyl shikimate as a substrate for CSE. Accordingly, recombinant CSE hydrolyzed caffeoyl shikimate into caffeate. Associated with the changes in lignin, the conversion of cellulose to glucose in cse mutants increased up to fourfold as compared to that in the wild type upon saccharification without pretreatment. Collectively, these data necessitate the revision of currently accepted models of the lignin biosynthetic pathway.

Expression of calmodulin genes in wild type and calmodulin mutants of Arabidopsis thaliana under heat stress

2010 ◽  
Vol 48 (8) ◽  
pp. 697-702 ◽  
Author(s):  
Nisreen A. AL-Quraan ◽  
Robert D. Locy ◽  
Narendra K. Singh
Keyword(s):  
Arabidopsis Thaliana ◽  
Heat Stress ◽  
Wild Type

Sucrose Transporter Gene AtSUC4 Responds to Drought Stress by Regulating the Sucrose Distribution and Metabolism in Arabidopsis thaliana

2013 ◽  
Vol 765-767 ◽  
pp. 2971-2975 ◽  
Author(s):  
Xue Gong ◽  
Ming Li Liu ◽  
Li Jun Zhang ◽  
Wei Liu ◽  
Che Wang
Keyword(s):  
Arabidopsis Thaliana ◽  
Drought Stress ◽  
Plant Stress ◽  
Homozygous Mutation ◽  
Transporter Gene ◽  
Wild Type ◽  
Sucrose Transporters ◽  
Whole Plant ◽  
Plant Stress Tolerance ◽  
Plant Level

Sucrose transporters (SUCs or SUTs) are considered as the important carriers and responsible for the loading, unloading and distribution of sucrose, but at present there is no report that SUCs are involved in sucrose distribution and metabolism under drought stress at the whole-plant level. AtSUC4, as the unique member of SUT4-clade inArabidopsis thaliana, may be important for plant stress tolerance. Here, by analyzing two homozygous mutation lines ofAtSUC4(Atsuc4-1andAtsuc4-2), we found drought stress induced higher sucrose, lower fructose and glucose contents in shoots, and lower sucrose, higher fructose and glucose contents in roots of these mutants compared with the wild-type (WT), leading to an imbalance of sucrose distribution, fructose and glucose (sucrose metabolites) accumulation changes at the whole-plant level. Thus we believe thatAtSUC4regulates sucrose distribution and metabolism in response to drought stress.

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