| 1. |
- Bellini, Catherine, et al.
(författare)
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Adventitious roots and lateral roots : similarities and differences
- 2014
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Ingår i: Annual Review of Plant Biology. - : Annual Reviews. - 1543-5008 .- 1545-2123. - 9780824306656 ; 65, s. 639-666
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Forskningsöversikt (refereegranskat)abstract
- In addition to its role in water and nutrient uptake, the root system is fundamentally important because it anchors a plant to its substrate. Although a wide variety of root systems exist across different species, all plants have a primary root (derived from an embryonic radicle) and different types of lateral roots. Adventitious roots, by comparison, display the same functions as lateral roots but develop from aerial tissues. In addition, they not only develop as an adaptive response to various stresses, such as wounding or flooding, but also are a key limiting component of vegetative propagation. Lateral and adventitious roots share key elements of the genetic and hormonal regulatory networks but are subject to different regulatory mechanisms. In this review, we discuss the developmental processes that give rise to lateral and adventitious roots and highlight knowledge acquired over the past few years about the mechanisms that regulate adventitious root formation.
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| 5. |
- Lakehal, Abdellah, et al.
(författare)
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A Molecular Framework for the Control of Adventitious Rooting by TIR1/AFB2-Aux/IAA-Dependent Auxin Signaling in Arabidopsis
- 2019
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Ingår i: Molecular Plant. - : Elsevier. - 1674-2052 .- 1752-9867. ; 12:11, s. 1499-1514
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Tidskriftsartikel (refereegranskat)abstract
- In Arabidopsis thaliana, canonical auxin-dependent gene regulation is mediated by 23 transcription factors from the AUXIN RESPONSE FACTOR (ARF) family that interact with auxin/indole acetic acid repressors (Aux/IAAs), which themselves form co-receptor complexes with one of six TRANSPORT INHIBITOR1/AUXIN-SIGNALLING F-BOX (TIR1/AFB) proteins. Different combinations of co-receptors drive specific sensing outputs, allowing auxin to control a myriad of processes. ARF6 and ARF8 are positive regulators of adventitious root initiation upstream of jasmonate, but the exact auxin co-receptor complexes controlling the transcriptional activity of these proteins has remained unknown. Here, using loss-of-function mutants we show that three Aux/IAA genes, IAA6, IAA9, and IAA17, act additively in the control of adventitious root (AR) initiation. These three IAA proteins interact with ARF6 and/or ARF8 and likely repress their activity in AR development. We show that TIR1 and AFB2 are positive regulators of AR formation and TIR1 plays a dual role in the control of jasmonic acid (JA) biosynthesis and conjugation, as several JA biosynthesis genes are up-regulated in the tir1-1 mutant. These results lead us to propose that in the presence of auxin, TIR1 and AFB2 form specific sensing complexes with IAA6, IAA9, and/or IAA17 to modulate JA homeostasis and control AR initiation.
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| 6. |
- Pacurar, Daniel Ioan, et al.
(författare)
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Auxin is a central player in the hormone cross-talks that control adventitious rooting
- 2014
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Ingår i: Physiologia Plantarum. - : John Wiley & Sons. - 0031-9317 .- 1399-3054. ; 151:1, s. 83-96
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Forskningsöversikt (refereegranskat)abstract
- Vegetative propagation of economically important woody, horticultural and agricultural species rely on an efficient adventitious root (AR) formation. The formation of ARs is a complex genetic trait regulated by the interaction of environmental and endogenous factors among which the phytohormone auxin plays an essential role. This article summarizes the current knowledge related to the intricate network through which auxin controls adventitious rooting. How auxin and recently identified auxin-related compounds affect AR formation in different plant species is discussed. Particular attention is addressed to illustrate how auxin has a central role in the hormone cross-talk leading to AR development. In parallel, we describe the molecular players involved in the control of auxin homeostasis, transport and signaling, for a better understanding of the auxin action during adventitious rooting.
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| 7. |
- Ranjan, Alok, et al.
(författare)
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Molecular basis of differential adventitious rooting competence in poplar genotypes
- 2022
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Ingår i: Journal of Experimental Botany. - : Oxford University Press. - 0022-0957 .- 1460-2431. ; 73:12, s. 4046-4064
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Tidskriftsartikel (refereegranskat)abstract
- Recalcitrant adventitious root (AR) development is a major hurdle in propagating commercially important woody plants. Although significant progress has been made to identify genes involved in subsequent steps of AR development, the molecular basis of differences in apparent recalcitrance to form AR between easy-to-root and difficult-to-root genotypes remains unknown. To address this, we generated cambium tissue-specific transcriptomic data from stem cuttings of hybrid aspen, T89 (difficult-to-root) and hybrid poplar OP42 (easy-to-root), and used transgenic approaches to verify the role of several transcription factors in the control of adventitious rooting. Increased peroxidase activity was positively correlated with better rooting. We found differentially expressed genes encoding reactive oxygen species scavenging proteins to be enriched in OP42 compared with T89. A greater number of differentially expressed transcription factors in cambium cells of OP42 compared with T89 was revealed by a more intense transcriptional reprograming in the former. PtMYC2, a potential negative regulator, was less expressed in OP42 compared with T89. Using transgenic approaches, we demonstrated that PttARF17.1 and PttMYC2.1 negatively regulate adventitious rooting. Our results provide insights into the molecular basis of genotypic differences in AR and implicate differential expression of the master regulator MYC2 as a critical player in this process.
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| 8. |
- Rigal, Adeline, et al.
(författare)
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The AINTEGUMENTA LIKE1 Homeotic Transcription Factor PtAIL1 controls the formation of Adventitious Root Primordia in Poplar
- 2012
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Ingår i: Plant Physiology. - : American Society of Plant Biologists. - 0032-0889 .- 1532-2548. ; 160:4, s. 1996-2006
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Tidskriftsartikel (refereegranskat)abstract
- Adventitious rooting is an essential but sometimes rate-limiting step in the clonal multiplication of elite tree germplasm, because the ability to form roots declines rapidly with age in mature adult plant tissues. In spite of the importance of adventitious rooting, the mechanism behind this developmental process remains poorly understood. We have described the transcriptional profiles that are associated with the developmental stages of adventitious root formation in the model tree poplar (Populus trichocarpa). Transcriptome analyses indicate a highly specific temporal induction of the AINTEGUMENTA LIKE1 (PtAIL1) transcription factor of the AP2 family during adventitious root formation. Transgenic poplar samples that overexpressed PtAIL1 were able to grow an increased number of adventitious roots, whereas RNA interference mediated the down-expression of PtAIL1 expression, which led to a delay in adventitious root formation. Microarray analysis showed that the expression of 15 genes, including the transcription factors AGAMOUS-Like6 and MYB36, was overexpressed in the stem tissues that generated root primordia in PtAIL1-overexpressing plants, whereas their expression was reduced in the RNA interference lines. These results demonstrate that PtAIL1 is a positive regulator of poplar rooting that acts early in the development of adventitious roots.
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