scholarly journals Transcriptomic and Anatomic Profiling Reveal Etiolation Promotes Adventitious Rooting by Exogenous Application of 1-Naphthalene Acetic Acid in Robinia pseudoacacia L.

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 789
Author(s):  
Muhammad Zeeshan Munir ◽  
Saleem Ud Din ◽  
Muhammad Imran ◽  
Zijie Zhang ◽  
Tariq Pervaiz ◽  
...  

The process of etiolation contributes significantly to vegetative propagation and root formation of woody plants. However, the molecular interaction pattern of different factors for etiolated adventitious root development in woody plants remains unclear. In the present study, we explored the changes at different etiolation stages of adventitious root formation in Robinia pseudoacacia. Histological and transcriptomic analyses were performed for the etiolated lower portion of hypocotyls to ascertain the adventitious root responses. We found that the dark-treated hypocotyls formed roots earlier than the control. Exogenous application of NAA (0.3 mg/L) stimulated the expressions of about 310 genes. Among these, 155 were upregulated and 155 were downregulated. Moreover, differentially expressed genes (DEGs) were significantly enriched in multiple pathways, including the biosynthesis of secondary metabolites, metabolic pathway, plant hormone signal transduction, starch and sucrose metabolism, phenylpropanoid biosynthesis, and carbon metabolism. These pathways could play a significant role during adventitious root formation in etiolated hypocotyls. The findings of this study can provide novel insights and a foundation for further studies to elucidate the connection between etiolation and adventitious root formation in woody plants.

2019 ◽  
Vol 20 (5) ◽  
pp. 1047 ◽  
Author(s):  
Jian Yu ◽  
Lijuan Niu ◽  
Jihua Yu ◽  
Weibiao Liao ◽  
Jianming Xie ◽  
...  

Calcium and ethylene are essential in plant growth and development. In this study, we investigated the effects of calcium and ethylene on adventitious root formation in cucumber explants under salt stress. The results revealed that 10 μM calcium chloride (CaCl2) or 0.1 μM ethrel (ethylene donor) treatment have a maximum biological effect on promoting the adventitious rooting in cucumber under salt stress. Meanwhile, we investigated that removal of ethylene suppressed calcium ion (Ca2+)-induced the formation of adventitious root under salt stress indicated that ethylene participates in this process. Moreover, the application of Ca2+ promoted the activities of 1-aminocyclopropane-l-carboxylic acid synthase (ACS) and ACC Oxidase (ACO), as well as the production of 1-aminocyclopropane-l-carboxylic acid (ACC) and ethylene under salt stress. Furthermore, we discovered that Ca2+ greatly up-regulated the expression level of CsACS3, CsACO1 and CsACO2 under salt stress. Meanwhile, Ca2+ significantly down-regulated CsETR1, CsETR2, CsERS, and CsCTR1, but positively up-regulated the expression of CsEIN2 and CsEIN3 under salt stress; however, the application of Ca2+ chelators or channel inhibitors could obviously reverse the effects of Ca2+ on the expression of the above genes. These results indicated that Ca2+ played a vital role in promoting the adventitious root development in cucumber under salt stress through regulating endogenous ethylene synthesis and activating the ethylene signal transduction pathway.


2020 ◽  
Vol 67 (1-2) ◽  
pp. 27-39 ◽  
Author(s):  
Alberto Pizarro ◽  
Carmen Díaz-Sala

Maturation-related decline of adventitious root formation is one of the major factors affecting adventitious rooting in forest tree species. We demonstrate that inhibition of polar auxin transport promoted cambium and xylem differentiation in rooting-competent hypocotyl cuttings from Pinus radiata under conditions of adventitious root formation. Treatments with bioactive gibberellins inhibited rooting while at the same time inducing both the differentiation of a continuous ring of cambium and xylem formation. Treatments with inhibitors of gibberellin biosynthesis did not affect the rooting response. The results demonstrate that xylem parenchyma and procambial cells at the xylem poles of rooting-competent hypocotyl cuttings after excision and under conditions of adventitious root induction become adventitious root meristems or xylem, depending on the directional auxin flow. Gibberellin may interact with this pathway, inducing xylem differentiation and inhibiting rooting. We conclude that modifications of auxin flow at the rooting sites, and the priming of cambial cells to differentiate into xylem during tree ageing, may be associated with the maturation-related decline of adventitious root formation.


2002 ◽  
Vol 21 (4) ◽  
pp. 296-314 ◽  
Author(s):  
David R. Smart ◽  
Laszlo Kocsis ◽  
M. Andrew Walker ◽  
Christine Stockert

2017 ◽  
Vol 8 ◽  
Author(s):  
Mohd Aslam ◽  
Parvaiz A. Raina ◽  
Rouf Ur Rafiq ◽  
T.O. Siddiqi ◽  
Zafar A. Reshi

Himalayan yew (<em>Taxus wallichiana</em> Zucc.), is an economically valuable plant and critically endangered due to overexploitation for the isolation of Taxol,an exciting anticancer drug from its bark and leaves. Since the species is unisexual and due to its long seed dormancy period and rapid loss of viability coupled with low survival percentage, its natural regeneration from seeds is very poor. As the seed raised plants add little growth, propagation by stem cuttings was tried under natural conditions and a considerable success was achieved after making use of different auxins (Indole-3- Acetic Acid-IAA, Indole Butyric Acid-IBA and Naphthalene Acetic Acid-NAA) in different concentrations. A Randomized block design (RBD) was adopted for laying the experiment of the present study. Of the ten treatments studied, IBA at 500ppm performed best of all the treatments and registered higher callusing percentage, rooting percentage, number of roots and length of roots in the juvenile shoot cuttings of the species. The results achieved through the application ofplant growth regulators (PGRs)by way of adventitious root formation (ARF) could be useful for the management of this understory coniferous tree species, whether for conservation, habitat restoration or for the production of Taxol,a promising anti-cancer agent. The technique evolved will be the most handy, quickest, inexpensive and can be applied any where in its natural habitat for the restoration and restocking of this valuable plant, which is otherwise facing the peril of extinction throughout the range of its distribution including Indian Himalayas.


Author(s):  
Xingqiang Fan ◽  
Hui Li ◽  
Yushuang Guo ◽  
Qi Qi ◽  
Xiangning Jiang ◽  
...  

Adventitious root (AR) formation is important for the vegetative propagation. The effects of strigolactones (SLs) on AR formation have been rarely reported, especially in woody plants. In this study, we first verified the inhibitory effects of SLs on AR formation in apple materials. Transcriptome analysis identified 12,051 differentially expressed genes over the course of AR formation, with functions related to organogenesis, cell wall biogenesis or plant senescence. WGCNA suggests SLs might inhibit AR formation through repressing the expression of two core hub genes, MdLAC3 and MdORE1. We further verified that enhanced cell wall formation and accelerated senescence were involved in the AR inhibition caused by SLs. Combining small RNA and degradome sequencing, as well as a dual-luciferase sensor system, we identified and validated three negatively correlated miRNA–mRNA pairs, including mdm-miR397–MdLAC3 involved in secondary cell wall formation, and mdm-miR164a/b–MdORE1 involved in senescence. Finally, we have experimentally demonstrated the role of mdm-miR164b–MdORE1 in SLs-mediated inhibition of AR formation. Overall, our findings not only propose a comprehensive regulatory network for the function of SLs on AR formation, but also provide novel candidate genes for the potential genetic improvement of AR formation in woody plants using transgenic or CRISPR technology.


Plants ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 321 ◽  
Author(s):  
Ricci Ada ◽  
Rolli Enrico

The success of vegetative propagation programmes strongly depends on adventitious rooting, a postembryonic developmental process whereby new roots can be induced from differentiated cells in positions where normally they do not arise. This auxin-dependent organogenesis has been studied at molecular, cellular, and developmental levels, and our knowledge of the process has improved in recent years. However, bioactive compounds that enhance adventitious root formation and possibly reduce undesirable auxinic side effects are still needed to ameliorate this process. From this point of view, our structure–activity relationship studies concerning urea derivatives revealed that some of them, more specifically, the N,N′-bis-(2,3-methylenedioxyphenyl)urea (2,3-MDPU), the N,N′-bis-(3,4-methylenedioxyphenyl)urea (3,4-MDPU), the 1,3-di(benzo[d]oxazol-5-yl)urea (5-BDPU), and the 1,3-di(benzo[d]oxazol-6-yl)urea (6-BDPU), constitute a category of adventitious rooting adjuvants. The results of our studies are presented here, in order either to highlight the positive effects of the supplementation of these urea derivatives, or to better understand the nature of their interaction with auxin.


HortScience ◽  
2019 ◽  
Vol 54 (9) ◽  
pp. 1551-1557 ◽  
Author(s):  
Fan Cao ◽  
Xinwang Wang ◽  
Zhuangzhuang Liu ◽  
Yongrong Li ◽  
Fangren Peng

Pecan cuttings are difficult for rooting. This study describes the pecan hardwood rooting process based on anatomic characteristics to understand root formation mechanisms of pecan cuttings. The expressed proteins of different periods during the adventitious rooting process of pecan seedling hardwood cuttings were identified and analyzed to evaluate the rooting mechanism. The expressed proteins of pecan cutting seedlings were also compared with other cultivar cuttings during the rooting period. Pecan seedling cuttings were developed at different air and substrate temperatures to induce root formation. Adventitious root formation of pecan hardwood cuttings was described, and the phloem at the base of the prepared cuttings was selected as the sample for the differential protein analysis. The results showed that adventitious root formation of pecan hardwood cuttings was the only product of callus differentiation, which originated from the cells of the cambium or vascular ray parenchyma. Such adventitious root primordia were developed from those calluses that formed the regenerative structure, and the expressed proteins during the adventitious rooting of pecan hardwood cutting were identified and analyzed by matrix-assisted laser desorption ionization–time of flight–mass spectrometry (MALDI-TOF-MS) to evaluate the rooting mechanism. Eight differentially expressed proteins were found in the rooting periods, and 15 differential proteins were found by comparing pecan cutting types, which were analyzed by peptide mass fingerprinting homology. The results show that the primordial cells were differentiated from the meristematic cells. Furthermore, the differentially expressed proteins contained energy metabolism proteins, adversity stress proteins, and signal transmission proteins. The energy metabolism-related proteins were adenosine triphosphate (ATP) synthase, photosynthesis-related proteins, and enolase. The adversity-stress proteins containing heat shock-related proteins and signal transmission proteins were mainly cytochrome enzymes and heme-binding proteins. Adventitious root formation of pecan cultivar hardwood cuttings was difficult. More trials should be performed from the potential aspects of high defensive protection and phloem morphologic structure.


Plants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 931 ◽  
Author(s):  
Aomei Li ◽  
Prakash Lakshmanan ◽  
Weizhong He ◽  
Hongwei Tan ◽  
Limin Liu ◽  
...  

Adventitious root (AR) formation was enhanced following the treatment of sugarcane microshoots with indole-3-butyric acid (IBA) and 1-naphthalene acetic acid (NAA) combined, suggesting that auxin is a positive regulator of sugarcane microshoot AR formation. The transcriptome profile identified 1737 and 1268 differentially expressed genes (DEGs) in the basal tissues (5 mm) of sugarcane microshoots treated with IBA+NAA compared to nontreated control on the 3rd and 7th days post-auxin or water treatment (days post-treatment—dpt), respectively. To understand the molecular changes, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed. This analysis showed that DEGs associated with the pathways were associated with plant hormone signaling, flavonoid and phenylpropanoid biosyntheses, cell cycle, and cell wall modification, and transcription factors could be involved in sugarcane microshoot AR formation. Furthermore, qRT–PCR analysis was used to validate the expression patterns of nine genes associated with root formation and growth, and the results were consistent with the RNA-seq results. Finally, a hypothetical hormonal regulatory working model of sugarcane microshoot AR formation is proposed. Our results provide valuable insights into the molecular processes associated with auxin-induced AR formation in sugarcane.


2016 ◽  
Vol 43 (1) ◽  
pp. 52 ◽  
Author(s):  
Carla E. Di Bella ◽  
Agustín A. Grimoldi ◽  
María S. Rossi Lopardo ◽  
Francisco J. Escaray ◽  
Edmundo L. Ploschuk ◽  
...  

Global change anticipates scenarios of sea level rise that would provoke long lasting floods, especially in lowland areas of salt marshes. Our aim was to evaluate the morpho-physiological adjustment ability to deal with continuous saline flooding of Spartina densiflora Brogn. plants from lowlands and uplands along a subtle topographical gradient (0.2 m differential altitude). Plants from both origins were subjected to continuous saline flooding (300 mM NaCl) for 35 days. Responses associated to adventitious rooting, aerenchyma formation, concentration of Na+, K+ and Cl– in roots and shoots tissues, tillering and growth were assessed. Root responses differentiated populations given that lowland plants showed higher ability for adventitious root formation and innate superior root ion regulation than upland plants. High constitutive K+ concentration plus high Na+ exclusion in root tissues led to significant low values of Na+ : K+ ratios in lowland plants. Better root functioning was, in turn, related with more consistent shoot performance as lowland plants maintained plant tiller number and shoot relative growth rate unaltered while upland plants decreased both parameters by 35 and 18%, respectively, when in saline flooding. The superior performance of lowland plants indicates that locally adapted populations can be promoted in salt marsh habitats with subtle differences at topographic level.


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