scholarly journals Variation of Response Patterns Associated with an Avirulent Plant Symbiont Directed Defense Gene Expressions in Maize Exposed to Toxic Elements

2021 ◽  
Vol 80 (1) ◽  
pp. 35-41
Author(s):  
Necla Pehlivan Gedik
2020 ◽  
Vol 3 (9) ◽  
pp. e202000775
Author(s):  
Wenshan Liu ◽  
Izailda Barbosa dos Santos ◽  
Anna Moye ◽  
Sang-Wook Park

In plants, growth-defense trade-offs occur because of limited resources, which demand prioritization towards either of them depending on various external and internal factors. However, very little is known about molecular mechanisms underlying their occurrence. Here, we describe that cyclophilin 20-3 (CYP20-3), a 12-oxo-phytodienoic acid (OPDA)–binding protein, crisscrosses stress responses with light-dependent electron reactions, which fine-tunes activities of key enzymes in plastid sulfur assimilations and photosynthesis. Under stressed states, OPDA, accumulates in the chloroplasts, binds and stimulates CYP20-3 to convey electrons towards serine acetyltransferase 1 (SAT1) and 2-Cys peroxiredoxin A (2CPA). The latter is a thiol-based peroxidase, protecting and optimizing photosynthesis by reducing its toxic byproducts (e.g., H2O2). Reduction of 2CPA then inactivates its peroxidase activity, suppressing the peroxide detoxification machinery, whereas the activation of SAT1 promotes thiol synthesis and builds up reduction capacity, which in turn triggers the retrograde regulation of defense gene expressions against abiotic stress. Thus, we conclude that CYP20-3 is a unique metabolic hub conveying resource allocations between plant growth and defense responses (trade-offs), ultimately balancing optimal growth phonotype.


2019 ◽  
Vol 47 (4) ◽  
pp. 1161-1167 ◽  
Author(s):  
Miao-Miao XIE ◽  
Yi-Can ZHANG ◽  
Li-Ping LIU ◽  
Ying-Ning ZOU ◽  
Qiang-Sheng WU ◽  
...  

Citrus canker is a quarantined disease, severely harming citrus plants. Soil beneficial arbuscular mycorrhizal fungi (AMF) can provide a biological control pathway to resist pathogens. This work was to test changes of signal substances including hydrogen peroxide (H2O2), nitric oxide (NO), calmodulin (CaM), salicylic acid (SA) and jasmonic acid (JA) and the pathogen defense gene expression in roots of AMF (Paraglomus occultum) and non-AMF trifoliate orange (Poncirus trifoliata) seedlings after infected by a expressions citrus canker pathogen (Xanthomonas axonopodis pv. Citri, Xac). AMF inoculation significantly improved plant height, stem diameter and leaf number. Xac infection dramatically decreased root H2O2, NO, and SA levels, but increased root CaM and JA concentrations in non-AMF seedlings. There were higher H2O2 and CaM levels and lower JA levels in Xac-infected seedlings than in non-Xac-infected seedlings under mycorrhization. Under non-Xac infection, mycorrhizal treatment reduced root H2O2, NO, and SA but increased CaM and JA levels. However, under Xac infection, mycorrhizal inoculation distinctly accelerated root H2O2, NO, CaM, and SA accumulation, accompanied with up-regulated expression levels of root PtEPS1 (enhance pseudomonas susceptibility 1) and PtPR4 (pathogenesis related gene 4), indicating that Xac stimulated mycorrhizal roles in enhancing resistance of citrus canker. Such results imply that citrus plants with pre-inoculated AMF had stronger resistance to Xac infection through increasing signal substrate accumulation and pathogen defense gene expressions.   ********* In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 4, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue. *********


1991 ◽  
Vol 34 (3) ◽  
pp. 671-678 ◽  
Author(s):  
Joan E. Sussman

This investigation examined the response strategies and discrimination accuracy of adults and children aged 5–10 as the ratio of same to different trials was varied across three conditions of a “change/no-change” discrimination task. The conditions varied as follows: (a) a ratio of one-third same to two-thirds different trials (33% same), (b) an equal ratio of same to different trials (50% same), and (c) a ratio of two-thirds same to one-third different trials (67% same). Stimuli were synthetic consonant-vowel syllables that changed along a place of articulation dimension by formant frequency transition. Results showed that all subjects changed their response strategies depending on the ratio of same-to-different trials. The most lax response pattern was observed for the 50% same condition, and the most conservative pattern was observed for the 67% same condition. Adult response patterns were most conservative across condition. Differences in discrimination accuracy as measured by P(C) were found, with the largest difference in the 5- to 6-year-old group and the smallest change in the adult group. These findings suggest that children’s response strategies, like those of adults, can be manipulated by changing the ratio of same-to-different trials. Furthermore, interpretation of sensitivity measures must be referenced to task variables such as the ratio of same-to-different trials.


Author(s):  
Barbara Kronsteiner ◽  
Panjaporn Chaichana ◽  
Manutsanun Sumonwiriya ◽  
Kemajitra Jenjaroen ◽  
Fazle Rabbi Chowdhury ◽  
...  

2011 ◽  
Vol 27 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Marleen M. Rijkeboer ◽  
Huub van den Bergh ◽  
Jan van den Bout

This study examines the construct validity of the Young Schema-Questionnaire at the item level in a Dutch population. Possible bias of items in relation to the presence or absence of psychopathology, gender, and educational level was analyzed, using a cross-validation design. None of the items of the YSQ exhibited differential item functioning (DIF) for gender, and only one item showed DIF for educational level. Furthermore, item bias analysis did not identify DIF for the presence or absence of psychopathology in as much as 195 of the 205 items comprising the YSQ. Ten items, however, spread over the questionnaire, were found to yield relatively inconsistent response patterns for patients and nonclinical participants.


Methodology ◽  
2011 ◽  
Vol 7 (3) ◽  
pp. 88-95 ◽  
Author(s):  
Jose A. Martínez ◽  
Manuel Ruiz Marín

The aim of this study is to improve measurement in marketing research by constructing a new, simple, nonparametric, consistent, and powerful test to study scale invariance. The test is called D-test. D-test is constructed using symbolic dynamics and symbolic entropy as a measure of the difference between the response patterns which comes from two measurement scales. We also give a standard asymptotic distribution of our statistic. Given that the test is based on entropy measures, it avoids smoothed nonparametric estimation. We applied D-test to a real marketing research to study if scale invariance holds when measuring service quality in a sports service. We considered a free-scale as a reference scale and then we compared it with three widely used rating scales: Likert-type scale from 1 to 5 and from 1 to 7, and semantic-differential scale from −3 to +3. Scale invariance holds for the two latter scales. This test overcomes the shortcomings of other procedures for analyzing scale invariance; and it provides researchers a tool to decide the appropriate rating scale to study specific marketing problems, and how the results of prior studies can be questioned.


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