scholarly journals 147 A 27-kDa Rhododendron Deacclimation Protein is Related to ABA Stress Ripening/Water Deficit Stress Inducible Family of Proteins

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 415A-415
Author(s):  
Rajeev Arora ◽  
Chon-Chong Lim

Many reports have shown the accumulation of specific proteins associated with cold acclimation in plants. However, there is a scarcity of data on the physiological and/or biochemical changes associated with deacclimation process. This study was initiated to determine protein changes specifically associated with deacclimation in Rhododendron. Current-year leaves were collected from three Rhododendron cultivars (`Chionoides', `Grumpy Yellow', and `Vulcanís Flame'; ≈4-year-old rooted cuttings) during natural non-acclimated (June), cold-acclimated (January), and deacclimated (May) state. Leaf freezing tolerance was evaluated using controlled freezing protocol (Lim et al. 1998, J. Amer. Soc. Hort. Sci. 123:246–252). Seasonal SDS-PAGE profiles exhibited a distinct accumulation of 27 kDa protein in deacclimated and nonacclimated tissues, but this protein was essentially undetectable in cold acclimated tissues of all three cultivars. Further characterization of this polypeptide, labeled as RhDAP27 (for rhododendron deacclimation protein), revealed that it has an iso-electric point of 6.5, has a compositional bias for Glu/Gln (13.9%), His (11.4%), Gly (11%), Ala (10%), Lys (8.3%), and Asp/Asn (8.1%)—hydrophilic amino acids constitutedabout 54% of the total amino acids while 40% were nonpolar, aliphatic amino acids (Gly, Ala, Val, Leu, Ile, Pro) and only 6% were aromatic amino acids (Phe and Tyr). Micro-sequencing of the four peptides produced by partial cleavage of RhDAP27 revealed a striking homology of RhDAP27 with two proteins (from Mesembryanthemum crystallinum and Pinus taeda) that belong to the family of ABA stress ripening/water deficit stress inducible proteins.

2021 ◽  
Vol 22 (10) ◽  
pp. 5314
Author(s):  
Marlon-Schylor L. le Roux ◽  
Nicolas Francois V. Burger ◽  
Maré Vlok ◽  
Karl J. Kunert ◽  
Christopher A. Cullis ◽  
...  

Drought response in wheat is considered a highly complex process, since it is a multigenic trait; nevertheless, breeding programs are continuously searching for new wheat varieties with characteristics for drought tolerance. In a previous study, we demonstrated the effectiveness of a mutant known as RYNO3936 that could survive 14 days without water. In this study, we reveal another mutant known as BIG8-1 that can endure severe water deficit stress (21 days without water) with superior drought response characteristics. Phenotypically, the mutant plants had broader leaves, including a densely packed fibrous root architecture that was not visible in the WT parent plants. During mild (day 7) drought stress, the mutant could maintain its relative water content, chlorophyll content, maximum quantum yield of PSII (Fv/Fm) and stomatal conductance, with no phenotypic symptoms such as wilting or senescence despite a decrease in soil moisture content. It was only during moderate (day 14) and severe (day 21) water deficit stress that a decline in those variables was evident. Furthermore, the mutant plants also displayed a unique preservation of metabolic activity, which was confirmed by assessing the accumulation of free amino acids and increase of antioxidative enzymes (peroxidases and glutathione S-transferase). Proteome reshuffling was also observed, allowing slow degradation of essential proteins such as RuBisCO during water deficit stress. The LC-MS/MS data revealed a high abundance of proteins involved in energy and photosynthesis under well-watered conditions, particularly Serpin-Z2A and Z2B, SGT1 and Calnexin-like protein. However, after 21 days of water stress, the mutants expressed ABC transporter permeases and xylanase inhibitor protein, which are involved in the transport of amino acids and protecting cells, respectively. This study characterizes a new mutant BIG8-1 with drought-tolerant characteristics suited for breeding programs.


1984 ◽  
Vol 62 (5) ◽  
pp. 276-279 ◽  
Author(s):  
C. H. Lin ◽  
W. Chung ◽  
K. P. Strickland ◽  
A. J. Hudson

An isozyme of S-adenosylmethionine synthetase has been purified to homogeneity by ammonium sulfate fractionation, DEAE-cellulose column chromatography, and gel filtration on a Sephadex G-200 column. The purified enzyme is very unstable and has a molecular weight of 120 000 consisting of two identical subunits. Amino acid analysis on the purified enzyme showed glycine, glutamate, and aspartate to be the most abundant and the aromatic amino acids to be the least abundant. It possesses tripolyphosphatase activity which can be stimulated five to six times by S-adenosylmethionine (20–40 μM). The findings support the conclusion that an enzyme-bound tripolyphosphate is an obligatory intermediate in the enzymatic synthesis of S-adenosylmethionine from ATP and methionine.


1999 ◽  
Vol 42 (6) ◽  
pp. 561-566 ◽  
Author(s):  
Qinhua Song ◽  
Yeping Xu ◽  
Shuqin Yu ◽  
Congxiang Chen ◽  
Xingxiao Ma ◽  
...  

2010 ◽  
Vol 48 (1) ◽  
pp. 35-44 ◽  
Author(s):  
Muthappa Senthil-Kumar ◽  
Ramanna Hema ◽  
Thumu Rao Suryachandra ◽  
H.V. Ramegowda ◽  
Ramaswamy Gopalakrishna ◽  
...  

2021 ◽  
Vol 12 ◽  
Author(s):  
Jeffrey P. Simpson ◽  
Jacob Olson ◽  
Brian Dilkes ◽  
Clint Chapple

The synthesis of small organic molecules, known as specialized or secondary metabolites, is one mechanism by which plants resist and tolerate biotic and abiotic stress. Many specialized metabolites are derived from the aromatic amino acids phenylalanine (Phe) and tyrosine (Tyr). In addition, the improved characterization of compounds derived from these amino acids could inform strategies for developing crops with greater resilience and improved traits for the biorefinery. Sorghum and other grasses possess phenylalanine ammonia-lyase (PAL) enzymes that generate cinnamic acid from Phe and bifunctional phenylalanine/tyrosine ammonia-lyase (PTAL) enzymes that generate cinnamic acid and p-coumaric acid from Phe and Tyr, respectively. Cinnamic acid can, in turn, be converted into p-coumaric acid by cinnamate 4-hydroxylase. Thus, Phe and Tyr are both precursors of common downstream products. Not all derivatives of Phe and Tyr are shared, however, and each can act as a precursor for unique metabolites. In this study, 13C isotopic-labeled precursors and the recently developed Precursor of Origin Determination in Untargeted Metabolomics (PODIUM) mass spectrometry (MS) analytical pipeline were used to identify over 600 MS features derived from Phe and Tyr in sorghum. These features comprised 20% of the MS signal collected by reverse-phase chromatography and detected through negative-ionization. Ninety percent of the labeled mass features were derived from both Phe and Tyr, although the proportional contribution of each precursor varied. In addition, the relative incorporation of Phe and Tyr varied between metabolites and tissues, suggesting the existence of multiple pools of p-coumaric acid that are fed by the two amino acids. Furthermore, Phe incorporation was greater for many known hydroxycinnamate esters and flavonoid glycosides. In contrast, mass features derived exclusively from Tyr were the most abundant in every tissue. The Phe- and Tyr-derived metabolite library was also utilized to retrospectively annotate soluble MS features in two brown midrib mutants (bmr6 and bmr12) identifying several MS features that change significantly in each mutant.


2021 ◽  
Author(s):  
Fatemeh Khakdan ◽  
Zahra Shirazi ◽  
Mojtaba Ranjbar

Abstract Methyl chavicol and methyl eugenol are important phenylpropanoid compounds previously purified from basil. These compounds are significantly enhanced by the water deficit stress-dependent mechanism. Here, for the first time, pObCVOMT and pObEOMT promoters were extracted by the genome walking method. They were then cloned into the upstream of the β-glucuronidase (GUS) reporter gene to identify the pattern of GUS water deficit stress-specific expression. Histochemical GUS assays showed in transgenic tobacco lines bearing the GUS gene driven by pObCVOMT and pObEOMT promoters, GUS was strongly expressed under water deficit stress. qRT-PCR analysis of pObCVOMT and pObEOMT transgenic plants confirmed the histochemical assays, indicating that the GUS expression is also significantly induced and up-regulated by increasing density of water deficit stress. This indicates these promoters are able to drive inducible expression. The cis-acting elements analysis showed that the pObCVOMT and pObEOMT promoters contained dehydration or water deficit-related transcriptional control elements.


1967 ◽  
Vol 13 (5) ◽  
pp. 581-586 ◽  
Author(s):  
S. P. Mathur ◽  
E. A. Paul

A strain of Penicillium frequentans was successfully employed for partial degradation and characterization of humic acids. Salicyl alcohol and salicylaldehyde were detected in culture filtrates of the fungus utilizing humates under reduced oxygen tension. The enzyme systems involved in the degradation of humic acids were adaptive. The humate-adapted mycelium was capable of metabolizing a number of compounds which occur in soil as products of degradation of lignin, aromatic amino acids, and plant glycosides but not polyphenolic hydrocarbons, resorcinol, and phloroglucinol.


Parasitology ◽  
1989 ◽  
Vol 99 (2) ◽  
pp. 265-274 ◽  
Author(s):  
G. W. P. Joshua ◽  
L. J. S. Harrison ◽  
M. M. H. Sewell

SummaryDirect surface I radio-isotope labelling techniques and SDS—PAGE analysis were used to compare the proteins and lentil—lectin adherent glycoproteins of the bovine stage of viable Taenia saginata larvae at three points in their development, the invasive oncospheres, immature (4-week-old) and mature (12 to 16-week-old) cysticerci. Some proteins and glycoproteins were present on all three of the ages of the parasite examined but there were also distinct age-specific proteins and glycoproteins detected on oncospheres and 4-week-old cysticerci and a marked difference between the protein/glycoprotein profiles of the parasite was apparent at these earlier stages of development and the mature cysticerci. The latter were characterized by the presence of high, 160–200 kDa molecular weight, lysine rich, glycoproteins, whereas small 16 and 18 kDa glycoproteins and a reduction-sensitive 23 kDa glycoprotein were first detected on 4-week-old immature cysticerci. Antigenic characterization of the isotope-labelled proteins and glycoproteins by immunoprecipitation against a panel of clinically defined bovine sera combined with SDS–PAGE analysis indicated that relatively few proteins were precipitated by sera from T. saginata-infected cattle as compared to the glycoproteins. However, both protein and glycoprotein antigens of possible protective and/or diagnostic significance were identified from oncospheres and cysticerci.


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