scholarly journals Jasmonate Signalling Contributes to Primary Root Inhibition Upon Oxygen Deficiency in Arabidopsis thaliana

Plants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1046 ◽  
Author(s):  
Vinay Shukla ◽  
Lara Lombardi ◽  
Ales Pencik ◽  
Ondrej Novak ◽  
Daan A. Weits ◽  
...  

Plants, including most crops, are intolerant to waterlogging, a stressful condition that limits the oxygen available for roots, thereby inhibiting their growth and functionality. Whether root growth inhibition represents a preventive measure to save energy or is rather a consequence of reduced metabolic rates has yet to be elucidated. In the present study, we gathered evidence for hypoxic repression of root meristem regulators that leads to root growth inhibition. We also explored the contribution of the hormone jasmonic acid (JA) to this process in Arabidopsis thaliana. Analysis of transcriptomic profiles, visualisation of fluorescent reporters and direct hormone quantification confirmed the activation of JA signalling under hypoxia in the roots. Further, root growth assessment in JA-related mutants in aerobic and anaerobic conditions indicated that JA signalling components contribute to active root inhibition under hypoxia. Finally, we show that the oxygen-sensing transcription factor (TF) RAP2.12 can directly induce Jasmonate Zinc-finger proteins (JAZs), repressors of JA signalling, to establish feedback inhibition. In summary, our study sheds new light on active root growth restriction under hypoxic conditions and on the involvement of the JA hormone in this process and its cross talk with the oxygen sensing machinery of higher plants.

2014 ◽  
Vol 7 (4) ◽  
pp. 616-625 ◽  
Author(s):  
Sulan Bai ◽  
Tao Yao ◽  
Miaomiao Li ◽  
Xiaomin Guo ◽  
Yaochuan Zhang ◽  
...  

2020 ◽  
Vol 10 ◽  
Author(s):  
Chuan-Ming Yeh ◽  
Koichi Kobayashi ◽  
Sho Fujii ◽  
Hidehiro Fukaki ◽  
Nobutaka Mitsuda ◽  
...  

2021 ◽  
Author(s):  
Nelson BC Serre ◽  
Dominik Kralík ◽  
Ping Yun ◽  
Sergey Shabala ◽  
Zdeněk Slouka ◽  
...  

AbstractThe existence of an electric gradient across membranes is essential for a cell operation. In plants, application of the growth regulator auxin (IAA) causes almost instantaneous membrane depolarization in various cell types, making membrane depolarization a hallmark of the rapid non-transcriptional responses to IAA. Auxin triggers rapid root growth inhibition; a process that underlies gravitropic bending. The growth and depolarization responses to auxin show remarkable similarities in dynamics, requirement of auxin influx and the involvement of the TIR1/AFB auxin coreceptors, but whether auxin-induced depolarization participates in root growth inhibition remains unanswered. Here, we established a toolbox to dynamically visualize membrane potential in vivo in Arabidopsis thaliana roots by combining the DISBAC2(3) fluorescent probe with microfluidics and vertical stage microscopy. This way we show that auxin-induced membrane depolarization tightly correlates with rapid root growth inhibition and that the cells of the transition zone/early elongation zone are the most responsive to auxin. Further, we demonstrate that auxin cycling in and out of the cells through AUX1 influx and PIN2 efflux is not essential for membrane depolarization and rapid root growth inhibition but acts as a facilitator of these responses. The rapid membrane depolarization by auxin instead strictly depends on the AFB1 auxin receptor, while the other TIR1/AFB paralogues contribute to this response. The lack of membrane depolarization in the afb1 mutant explains the lack of the immediate root growth inhibition. Finally, we show that AFB1 is required for the rapid depolarization and rapid growth inhibition of cells at the lower side of the gravistimulated root. These results are instrumental in understanding the physiological significance of membrane depolarization for the gravitropic response of the root and clarify the role of AFB1 as the receptor central for rapid auxin responses, adding another piece to the puzzle in understanding the biology of the phytohormone auxin.


Author(s):  
Yupu Huang ◽  
Sheliang Wang ◽  
Lei Shi ◽  
Fangsen Xu

Abstract Boron (B) is an essential micronutrient for plant growth and development. Jasmonic acid (JA) plays pivotal roles in plant growth. However, the underlying molecular mechanism of JA involvement in B-deficiency-induced root growth inhibition is yet to be explored. In this study, we investigated the response of JA to B deficiency and the mechanism of JAR1-dependent JA signaling in root growth inhibition under B deficiency. B deficiency enhanced JA signaling in roots, and root growth inhibition was partially restored by JA biosynthesis inhibition. jar1-1 (jasmonate-resistant 1, JAR1) mutant, mutants of coronatine-insensitive 1 (coi1-2) and myc2 defective in JA signaling showed insensitivity to B deficiency. Ethylene-overproduction mutant eto1 and ethylene-insensitive mutant etr1 showed sensitivity and insensitivity to B deficiency, respectively, suggesting that ethylene is involved in the inhibition of primary root growth under B deficiency. Furthermore, after a declined in EIN3 protein levels, which may contribute to root growth, ethylene signaling was weakened in the jar1-1 mutant root under B deficiency. Under B deficiency, B concentrations were increased in the roots and shoots of the jar1-1 mutant, owing to the large root system and its activity. Therefore, our findings revealed that JA, which is involved in the inhibition of root growth under B deficiency, is regulated by JAR1 activated JA and ethylene signaling pathways.


Author(s):  
Doris Fovwe Ogeleka ◽  
Esther Obasi

Introduction: The constant impact on the environment occasioned by pollution, indiscriminate application of agricultural chemicals, security challenges and crisis in the Niger Delta ecological area of Nigeria has caused severe damage to plants, soil organisms and humans. Aim and Methodology: In this research, onions (Allium cepa L) was exposed to varying concentrations of an atrazine-based selective herbicide Arda-force® to estimate the phyto-toxic effects on the plant species using the Organization for Economic Co-operation and Development, (OECD) protocol #208. Results: The mean effective concentration (EC50) using root growth inhibition produced indications of phyto-toxicity to the exposed species at a concentration of 0.55 ± 0.06 mg/L. Similarly, the maximum root growth inhibition efficiency relative to the control was 65% as recorded in the highest test concentration of 1.25 mg/L. Discussion: The study indicated that constant application / indiscriminate use of the herbicide Arda-force® could cause deleterious influence on these plant and vegetable species, daily consumed by humans as a rich source of anti-oxidants. Conclusion: This study concluded that atrazine-based herbicide Arda-force® used in this assessment resulted in phyto-toxic effects to Allium cepa L. At the exposed concentrations of the herbicide to non-target specie – Allium cepa L. that are integral parts of the ecosystems, the ‘‘harmless’’ status of atrazine acclaimed by the United State Environmental Protection Agency (USEPA) is still very much in doubt.


Planta ◽  
2011 ◽  
Vol 234 (6) ◽  
pp. 1163-1177 ◽  
Author(s):  
Alejandra Hernández-Barrera ◽  
Yamel Ugartechea-Chirino ◽  
Svetlana Shishkova ◽  
Selene Napsucialy-Mendivil ◽  
Aleš Soukup ◽  
...  

Plant Science ◽  
2020 ◽  
Vol 293 ◽  
pp. 110418
Author(s):  
Iñigo Saiz-Fernández ◽  
Maite Lacuesta ◽  
Usue Pérez-López ◽  
M. Carmen Sampedro ◽  
Ramon J. Barrio ◽  
...  

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