Changes in homogalacturonans and enzymes degrading them during cotton cotyledon expansion

2007 ◽  
Vol 68 (8) ◽  
pp. 1094-1103 ◽  
Author(s):  
Zhiquan Zhang ◽  
Margaret L. Pierce ◽  
Andrew J. Mort
Keyword(s):  
Cotyledon Expansion

scholarly journals The CBL-Interacting Protein Kinase NtCIPK23 Positively Regulates Seed Germination and Early Seedling Development in Tobacco (Nicotiana tabacum L.)

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 323
Author(s):  
Sujuan Shi ◽  
Lulu An ◽  
Jingjing Mao ◽  
Oluwaseun Olayemi Aluko ◽  
Zia Ullah ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Seed Germination ◽  
Seedling Growth ◽  
Hypocotyl Elongation ◽  
Interacting Protein ◽  
Knock Out ◽  
Early Seedling Growth ◽  
Tobacco Seedlings ◽  
Early Seedling ◽  
Cotyledon Expansion

CBL-interacting protein kinase (CIPK) family is a unique group of serine/threonine protein kinase family identified in plants. Among this family, AtCIPK23 and its homologs in some plants are taken as a notable group for their importance in ions transport and stress responses. However, there are limited reports on their roles in seedling growth and development, especially in Solanaceae plants. In this study, NtCIPK23, a homolog of AtCIPK23 was cloned from Nicotiana tabacum. Expression analysis showed that NtCIPK23 is mainly expressed in the radicle, hypocotyl, and cotyledons of young tobacco seedlings. The transcriptional level of NtCIPK23 changes rapidly and spatiotemporally during seed germination and early seedling growth. To study the biological function of NtCIPK23 at these stages, the overexpressing and CRISPR/Cas9-mediated knock-out (ntcipk23) tobacco lines were generated. Phenotype analysis indicated that knock-out of NtCIPK23 significantly delays seed germination and the appearance of green cotyledon of young tobacco seedling. Overexpression of NtCIPK23 promotes cotyledon expansion and hypocotyl elongation of young tobacco seedlings. The expression of NtCIPK23 in hypocotyl is strongly upregulated by darkness and inhibited under light, suggesting that a regulatory mechanism of light might underlie. Consistently, a more obvious difference in hypocotyl length among different tobacco materials was observed in the dark, compared to that under the light, indicating that the upregulation of NtCIPK23 contributes greatly to the hypocotyl elongation. Taken together, NtCIPK23 not only enhances tobacco seed germination, but also accelerate early seedling growth by promoting cotyledon greening rate, cotyledon expansion and hypocotyl elongation of young tobacco seedlings.

scholarly journals Plant Regeneration via Somatic Embryogenesis from Leaf and Floral Explants of ‘Chancellor’ Wine Grape

1970 ◽  
Vol 20 (2) ◽  
pp. 157-170 ◽  
Author(s):  
Richard M.S. Mulwa ◽  
Margaret M.A. Norton ◽  
Robert M. Skirvin
Keyword(s):  
Somatic Embryogenesis ◽  
Embryogenic Callus ◽  
Somatic Embryos ◽  
Basal Medium ◽  
Limiting Factor ◽  
Half Strength ◽  
Conversion Stage ◽  
Cotyledon Expansion ◽  
Floral Explants ◽  
Shoot Meristems

Abundant embryogenic callus was obtained from leaf and floral explants of "Chancellor" grape by continuous culture for 12 weeks on Nitsch and Nitsch basal medium supplemented with 9 μM 2, 4-D + 17 μM IASP + either 1 μM BA or 1 μM TDZ (ECIM) in darkness. They were successfully maintained by a five to six week subculture interval on NN medium containing 2 μM 2, 4-D + 0.2 μM TDZ + 4 μM IASP (LTMM). Near synchronous embryo developed from embryogenic callus on medium containing 10 μM IASP + 8 μM NOA + 1 μM TDZ + 1 μM ABA + 2.5 g/l AC (EDMM).  Individually separated somatic embryos were germinated on both NN and half strength of MS containing 0.5 μM BA + 0.025 μM NAA, respectively; normal plantlet conversion from embryos was low (35%).  Whole fruiting plants were obtained. Aberrant embryo development was characterized by failure to form functional shoot meristems following the initial cotyledon expansion during germination. These observations indicate that the embryo conversion stage of the regeneration is difficult and remains a limiting factor requiring more empirical experimentation for improvement in grape tissue culture.   Key words: Chancellor grape, Regeneration, Somatic embryogenesis   D.O.I. 10.3329/ptcb.v20i2.6895   Plant Tissue Cult. & Biotech. 20(2): 157-170, 2010 (December)

scholarly journals Bioreactors in coffee micropropagation

2006 ◽  
Vol 18 (1) ◽  
pp. 45-54 ◽  
Author(s):  
Hervé Etienne ◽  
E Dechamp ◽  
D Barry-Etienne ◽  
Bernóit Bertrand
Keyword(s):  
Somatic Embryogenesis ◽  
Scaling Up ◽  
Coffea Canephora ◽  
Root Tip ◽  
Temporary Immersion ◽  
Axis Elongation ◽  
Cotyledon Expansion ◽  
Tip Formation ◽  
Embryogenic Tissues ◽  
Rapid Mass

In coffee, bioreactors are the most promising way for scaling-up micropropagation processes, particularly somatic embryogenesis. The availability of an efficient somatic embryogenesis process would allow the rapid mass production of heterozygous materials such as selected Coffea canephora clones and F1 Arabica hybrid varieties. For the last fifteen years, bioreactors (mechanically or pneumatically agitated bioreactors, temporary immersion bioreactors) have mostly been used on coffee to optimize the mass regeneration of somatic embryos from embryogenic tissues. This review presents the main results, obtained with several bioreactor models, concerning the different steps of the micropropagation process : i) the multiplication of embryogenic tissues, ii) the somatic embryo mass regeneration and iii) the production of pre-germinated embryos and plantlets in bioreactors. The literature shows that scaling-up can be successful, since very efficient embryo production has been achieved for both C. arabica and C. canephora. Moreover, it was proven that the pre-germinated coffee embryos - i.e. embryonic axis elongation (10-12 mm), root tip formation, cotyledon expansion and greening - obtained in temporary immersion bioreactors were photoautotrophic and able to regenerate vigorous plantlets after sowing under nursery conditions. The feasibility to apply the bioreactor technology in an industrial micropropagation procedure is also discussed in the particular socio-economic context of coffee growing.

scholarly journals Light-Stimulated Cotyledon Expansion in Arabidopsis Seedlings (The Role of Phytochrome B)

1994 ◽  
Vol 104 (3) ◽  
pp. 1027-1032 ◽  
Author(s):  
M. M. Neff ◽  
E. Van Volkenburgh
Keyword(s):  
Phytochrome B ◽  
Cotyledon Expansion

scholarly journals Light-Stimulated Cotyledon Expansion in the blu3 and hy4 Mutants of Arabidopsis thaliana

1994 ◽  
Vol 105 (4) ◽  
pp. 1433-1436 ◽  
Author(s):  
D. E. Blum ◽  
M. M. Neff ◽  
E. Van Volkenburgh
Keyword(s):  
Arabidopsis Thaliana ◽  
Cotyledon Expansion

Synthesis and preliminary bioactivity evaluation of new pregnane brassinosteroid-like compounds

2005 ◽  
Vol 83 (8) ◽  
pp. 1084-1092 ◽  
Author(s):  
Daniel G Rivera ◽  
Francisco Coll
Keyword(s):  
Hydrogen Bond ◽  
Plant Growth ◽  
Hypocotyl Elongation ◽  
Hydrogen Bond Donor ◽  
Donor And Acceptor ◽  
Plant Growth Promoting ◽  
Plant Growth Promoting Activity ◽  
Growth Promoting ◽  
Cotyledon Expansion

Seven new pregnane compounds bearing some representative A- and B-ring brassinosteroid functions, as well as hydrogen bond donor and acceptor ones on the D ring, were efficiently synthesized. The obtained compounds did not show remarkable plant growth-promoting activity in the radish hypocotyl elongation and cotyledon expansion bioassays, however, introducing oxygen and amino functions on the D ring led to an enhancement of the bioactivity. The 16β-functionalized pregnane brassinosteroid-like compounds were slightly more active than the 16α-functionalized ones.Key words: steroids, brassinosteroids, pregnane analogues.

scholarly journals Arabidopsis SAURs are critical for differential light regulation of the development of various organs

2016 ◽  
Vol 113 (21) ◽  
pp. 6071-6076 ◽  
Author(s):  
Ning Sun ◽  
Jiajun Wang ◽  
Zhaoxu Gao ◽  
Jie Dong ◽  
Hang He ◽  
...  
Keyword(s):  
Phosphatase Activity ◽  
Protein Phosphatases ◽  
Light Regulation ◽  
Differential Regulation ◽  
Cell Enlargement ◽  
Differential Growth ◽  
Genes Encoding ◽  
Organ Specific ◽  
Cotyledon Expansion ◽  
Mutation Analyses

During deetiolation of Arabidopsis seedlings, light promotes the expansion of cotyledons but inhibits the elongation of hypocotyls. The mechanism of this differential regulation of cell enlargement is unclear. Our organ-specific transcriptomic analysis identified 32 Small Auxin Up RNA (SAUR) genes whose transcripts were light-induced in cotyledons and/or repressed in hypocotyls. We therefore named these SAURs as lirSAURs. Both overexpression and mutation analyses demonstrated that lirSAURs could promote cotyledon expansion and opening and enhance hypocotyl elongation, possibly by inhibiting phosphatase activity of D-clade type 2C protein phosphatases (PP2C-Ds). Light reduced auxin levels to down-regulate the expression of lirSAURs in hypocotyls. Further, phytochrome-interacting factors (PIFs) were shown to directly bind the genes encoding these SAURs and differentially regulate their expression in cotyledons and hypocotyls. Together, our study demonstrates that light mediates auxin levels and PIF stability to differentially regulate the expression of lirSAURs in cotyledons and hypocotyls, and these lirSAURs further mediate the differential growth of these two organs.

scholarly journals 229 Solid Matrix Priming of Gourd Seeds for Fast and Uniform Germination

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 481E-481
Author(s):  
Hae-Jeen Bang ◽  
Soo-Jung Hwang ◽  
Hyun-Sook Ham ◽  
Jung-Myung Lee
Keyword(s):  
Seed Germination ◽  
Early Stage ◽  
Germination Percentage ◽  
Solid Matrix ◽  
Dry Heat ◽  
Heat Treated ◽  
Early Germination ◽  
Chemical Solutions ◽  
Dry Heat Treatment ◽  
Cotyledon Expansion

Grafting is common in all cucurbits in Asia, and gourd (Lagenaria siceraria) is the most popular rootstock for watermelons. Since the grafting is practiced at very early stage (right after the cotyledon expansion), uniform germination of rootstocks as well as the scions is crucial for grafting efficiency. Seeds were divided into three groups; intact, dry-heat treated (75 °C for 72 h), and brushed (575 rpm for 5 min). In each group, various solid matrix priming (SMP) treatments were imposed. Microcel E was used for SMP treatment with water or chemical solutions (10 seed: 1 Microcel E: 3 water, by weight). SMP treatment promoted earlier seed germination in all tested cultivars, thus resulting in higher rate of graftable seedlings. Brushing before SMP further enhanced earlier and uniform seed germination. Dry heat treatment, which can eliminated the seed-borne Fusarium spp. and virus, significantly delayed the early germination although the final germination percentage was not influenced. The characteristics of seedlings will also be presented.

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