scholarly journals The cytokinin response factors modulate root and shoot growth and promote leaf senescence in Arabidopsis

2015 ◽  
Vol 85 (1) ◽  
pp. 134-147 ◽  
Author(s):  
Tracy Raines ◽  
Carly Shanks ◽  
Chia-Yi Cheng ◽  
Duncan McPherson ◽  
Cristiana T. Argueso ◽  
...  

Development ◽  
2020 ◽  
Vol 147 (20) ◽  
pp. dev191734
Author(s):  
Christian A. Burr ◽  
Jinjing Sun ◽  
Maria V. Yamburenko ◽  
Andrew Willoughby ◽  
Charles Hodgens ◽  
...  

ABSTRACTThe phytohormone cytokinin regulates diverse aspects of plant growth and development. Our understanding of the metabolism and perception of cytokinin has made great strides in recent years, mostly from studies of the model dicot Arabidopsis. Here, we employed a CRISPR/Cas9-based approach to disrupt a subset of cytokinin histidine kinase (HK) receptors in rice (Oryza sativa) in order to explore the role of cytokinin in a monocot species. In hk5 and hk6 single mutants, the root growth, leaf width, inflorescence architecture and/or floral development were affected. The double hk5 hk6 mutant showed more substantial defects, including severely reduced root and shoot growth, a smaller shoot apical meristem, and an enlarged root cap. Flowering was delayed in the hk5 hk6 mutant and the panicle was significantly reduced in size and infertile due to multiple defects in floral development. The hk5 hk6 mutant also exhibited a severely reduced cytokinin response, consistent with the developmental phenotypes arising from a defect in cytokinin signaling. These results indicate that HK5 and HK6 act as cytokinin receptors, with overlapping functions to regulate diverse aspects of rice growth and development.



2016 ◽  
Vol 5 (12) ◽  
pp. 5179
Author(s):  
Ilahi Shaik* ◽  
P. Janakiram ◽  
Sujatha L. ◽  
Sushma Chandra

Indole acetic acid is a natural phytohormone which influence the root and shoot growth of the plants. Six (GM1-GM6) endosymbiotic bacteria are isolated from Gracilaria corticata and screened for the production of IAA out of six, three bacterial strains GM3, GM5 and GM6 produced significant amount of IAA 102.4 µg/ml 89.40 µg/ml 109.43 µg/ml respectively. Presence of IAA in culture filtrate of the above strains is further analyzed and confirmed by TLC. As these bacterial strains, able to tolerate the high salinity these can be effectively used as PGR to increase the crop yield in saline soils.



2021 ◽  
Vol 72 (8) ◽  
pp. 3294-3306
Author(s):  
Ariel M Hughes ◽  
H Tucker Hallmark ◽  
Lenka Plačková ◽  
Ondrej Novák ◽  
Aaron M Rashotte

Abstract Cytokinin response factors (CRFs) are transcription factors that are involved in cytokinin (CK) response, as well as being linked to abiotic stress tolerance. In particular, oxidative stress responses are activated by Clade III CRF members, such as AtCRF6. Here we explored the relationships between Clade III CRFs and oxidative stress. Transcriptomic responses to oxidative stress were determined in two Clade III transcription factors, Arabidopsis AtCRF5 and tomato SlCRF5. AtCRF5 was required for regulated expression of >240 genes that are involved in oxidative stress response. Similarly, SlCRF5 was involved in the regulated expression of nearly 420 oxidative stress response genes. Similarities in gene regulation by these Clade III members in response to oxidative stress were observed between Arabidopsis and tomato, as indicated by Gene Ontology term enrichment. CK levels were also changed in response to oxidative stress in both species. These changes were regulated by Clade III CRFs. Taken together, these findings suggest that Clade III CRFs play a role in oxidative stress response as well as having roles in CK signaling.



Geoderma ◽  
2016 ◽  
Vol 265 ◽  
pp. 1-5 ◽  
Author(s):  
J. Lipiec ◽  
A. Siczek ◽  
A. Sochan ◽  
A. Bieganowski


2018 ◽  
Vol 222 ◽  
pp. 86-93 ◽  
Author(s):  
Kare P. Mahmud ◽  
Bruno P. Holzapfel ◽  
Yann Guisard ◽  
Jason P. Smith ◽  
Sharon Nielsen ◽  
...  


2016 ◽  
Vol 46 (3) ◽  
pp. 506-512 ◽  
Author(s):  
Athos Odin Severo Dorneles ◽  
Aline Soares Pereira ◽  
Liana Verônica Rossato ◽  
Gessieli Possebom ◽  
Victória Martini Sasso ◽  
...  

ABSTRACT: Aluminum (Al) is highly toxic to plants, causing stress and inhibiting growth and silicon (Si) is considered beneficial for plants. This chemical element has a high affinity with Al. The aim of this study was to investigate the potential of Si to mitigate the toxic effects of Al on potato ( Solanum tuberosum L.) plants and assess whether this behavior is different among genotypes with differing degrees of sensitivity to Al. Potato plants of the genotypes SMIJ319-7 (Al-sensitive) and SMIF212-3 (Al-tolerant) were grown for fourteen days in nutrient solution (without P and pH 4.5±0.1) under exposure to combinations of Al (0 and 1.85mM) and Si (0, 0.5 and 1.0mM). After this period, shoot and roots of the two genotypes were collected to determine Al content in tissues and assess morphological parameters of root and shoot growth. Roots of both genotypes accumulated more Al than shoots and the Al-tolerant genotype accumulated more Al than the sensitive one, both in roots and in shoot. Furthermore, the presence of 0.5 and 1.0mM Si together with Al reduced the Al content in shoot in both genotypes and in roots of the Al-tolerant genotype, respectively. Si ameliorated the toxic effects of Al with regard to number of root branches and leaf number in both potato genotypes. Si has the potential to mitigate the toxic effects of Al in potato plants regardless of Al sensitivity.



Hereditas ◽  
2010 ◽  
Vol 147 (3) ◽  
pp. 114-122 ◽  
Author(s):  
H. Bchini ◽  
M. Ben Naceur ◽  
R. Sayar ◽  
H. Khemira ◽  
L. Ben Kaab-Bettaeïb


1981 ◽  
Vol 97 (1) ◽  
pp. 119-124 ◽  
Author(s):  
I. P. S. Ahlawat ◽  
C. S. Saraf

SUMMARYField studies were made for 2 years on a sandy loam soil under dryland conditions of north-west India with three pigeon-pea varieties in relation to plant density and the application of phosphate fertilizer. Varieties Pusa Ageti and P4785 with better developed root system and profuse nodulation had higher grain and stalk yield, and higher N and P yield than Prabhat. Root and shoot growth and root nodulation were adversely affected with increasing plant densities in the range 50 × 103 and 150 × 103 plants/ha. Stalk and total N and P yield increased with increasing plant density. Plant density of 117 × 103 plants/ha produced maximum grain yield of 1·53 t/ha. Phosphorus fertilizer promoted root and shoot growth, intensity and volume of nodulation and increased grain, stalk, N and P yield. The effect of plant density on grain yield was more pronounced in the presence of phosphate fertilizer. The economic optimum rate of P ranged between 22·1 and 23·1 kg/ha under different plant densities.



2011 ◽  
Vol 29 (4) ◽  
pp. 220-222
Author(s):  
Kathryne J. Jernigan ◽  
Amy N. Wright

Abstract Research was conducted to screen four landscape shrub taxa for tolerance to repeated flooding events. Plants of Fothergilla × intermedia ‘Mt. Airy’ (dwarf witchalder), Ilex verticillata ‘Winter Red’ (winterberry), Clethra alnifolia ‘Ruby Spice’ (summersweet), and Viburnum nudum Brandywine™ (possumhaw) were flooded repeatedly over six weeks for 0 (non-flooded), 3, or 6 days with a draining period of 6 days between each flooding event. The experiment was repeated for a total of two runs. With the exception of F. × intermedia ‘Mt. Airy’, all taxa showed good visual quality and no reduction in root growth in either run, and effects on shoot growth were minimal. Size index of Clethra alnifolia ‘Ruby Spice’ was 27% higher in plants flooded for 0 or 3 days than in plants flooded for 6 days in run 1 only. Shoot dry weight of Ilex verticillata ‘Winter Red’ was actually 11% higher in plants flooded 6 days days than in plants flooded for 0 or 3 days in run 2. Size index of Viburnum nudum Brandywine™ increased with increasing flood length, and plants flooded for 6 days had a 9% higher SI than plants flooded for 0 days in run 1. With the exception of Fothergilla × intermedia L. ‘Mt. Airy’, all taxa appeared tolerant of and even thrived during flooding and would be appropriate shrub selections for a southeastern United States rain garden.



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