Daily temperature extremes as an indicator of high temperature stress

Soil Research ◽  
1991 ◽  
Vol 29 (3) ◽  
pp. 377 ◽  
Author(s):  
KL Bristow ◽  
DG Abrecht

Theory outlining a general relationship between stress experienced by an organism exposed to supra-optimal temperatures and daily temperature extremes is discussed. It is shown that useful nomograms relating Tmax, Tmin, Tcritical, and high temperature stress can be developed and that these nomograms are not particularly sensitive to changes in daylength (caused by changes in time of year or latitude). Sensitivity of high temperature stress to changes in Tmin is also considerably less than that to changes in Tmax, suggesting that in situations where Tmin, does not vary greatly, Tmax alone can be used as an indicator of high temperature stress. Application of these concepts is illustrated by analyses of high temperature stress in pre-emergent maize seedlings. Results show that Tmax alone can account for more than 90% of the variation in the reduction of shoot length due to the occurrence of supra-optimal temperatures.

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 477
Author(s):  
Zhenqing Xia ◽  
Guixin Zhang ◽  
Shibo Zhang ◽  
Qi Wang ◽  
Yafang Fu ◽  
...  

In the context of global warming, the effects of warming in the root zone of crops on maize seedling characteristics deserve research attention. Previous studies on the adaptive traits of dryland maize have mainly focused on soil moisture and nutrients, rather than analyzing potential factors for the adaptive traits of root zone warming. This study was conducted to investigate the effects of different root zone warming ranges on the agronomic traits, hormones, and microstructures of maize seedling roots and leaves. The results showed that minor increases in the root zone temperature significantly enhanced maize seedling growth. However, when the temperature in the root zone was excessive, the stem diameter, root surface area, root volume, total root length, dry matter accumulation, and root/shoot biomass of maize seedlings sharply decreased. Under high temperature stress in the root zone, the root conduit area; root stele diameter; root content of trans-zeatin (ZT), gibberellin A3 (GA3), and indoleacetic acid (IAA); leaf thickness; upper and lower epidermis thickness; and leaf content of ZT and GA3 were significantly decreased. The hormone content and microstructure changes might be an important reason for root growth maldevelopment and nutrient absorption blockage, and they also affected the leaf growth of maize seedlings. Compared with the ‘senescent’ maize type Shaandan 902 (SD902), the plant microstructure of the ‘stay-green’ maize type Shaandan 609 (SD609) was less affected by increased temperatures, and the ability of the root system to absorb and transport water was stronger, which might explain its tolerance of high temperature stress in the root zone.


2020 ◽  
Vol 53 (2) ◽  
Author(s):  
Khalil Ahmed Laghari ◽  
Abdul Jabbar Pirzada ◽  
Mahboob Ali Sial ◽  
Muhammad Athar Khan ◽  
Jamal Uddin Mangi

Author(s):  
D-J Kim ◽  
I-G Kim ◽  
J-Y Noh ◽  
H-J Lee ◽  
S-H Park ◽  
...  

Abstract As DRAM technology extends into 12-inch diameter wafer processing, plasma-induced wafer charging is a serious problem in DRAM volume manufacture. There are currently no comprehensive reports on the potential impact of plasma damage on high density DRAM reliability. In this paper, the possible effects of floating potential at the source/drain junction of cell transistor during high-field charge injection are reported, and regarded as high-priority issues to further understand charging damage during the metal pad etching. The degradation of block edge dynamic retention time during high temperature stress, not consistent with typical reliability degradation model, is analyzed. Additionally, in order to meet the satisfactory reliability level in volume manufacture of high density DRAM technology, the paper provides the guidelines with respect to plasma damage. Unlike conventional model as gate antenna effect, the cell junction damage by the exposure of dummy BL pad to plasma, was revealed as root cause.


2020 ◽  
Vol 16 (2) ◽  
pp. 18-23
Author(s):  
K. PRAVALLIKA ◽  
C. ARUNKUMAR ◽  
A. VIJAYKUMAR ◽  
R. BEENA ◽  
V. G. JAYALEKSHMI

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 687
Author(s):  
Chan Seop Ko ◽  
Jin-Baek Kim ◽  
Min Jeong Hong ◽  
Yong Weon Seo

High-temperature stress during the grain filling stage has a deleterious effect on grain yield and end-use quality. Plants undergo various transcriptional events of protein complexity as defensive responses to various stressors. The “Keumgang” wheat cultivar was subjected to high-temperature stress for 6 and 10 days beginning 9 days after anthesis, then two-dimensional gel electrophoresis (2DE) and peptide analyses were performed. Spots showing decreased contents in stressed plants were shown to have strong similarities with a high-molecular glutenin gene, TraesCS1D02G317301 (TaHMW1D). QRT-PCR results confirmed that TaHMW1D was expressed in its full form and in the form of four different transcript variants. These events always occurred between repetitive regions at specific deletion sites (5′-CAA (Glutamine) GG/TG (Glycine) or (Valine)-3′, 5′-GGG (Glycine) CAA (Glutamine) -3′) in an exonic region. Heat stress led to a significant increase in the expression of the transcript variants. This was most evident in the distal parts of the spike. Considering the importance of high-molecular weight glutenin subunits of seed storage proteins, stressed plants might choose shorter polypeptides while retaining glutenin function, thus maintaining the expression of glutenin motifs and conserved sites.


2018 ◽  
pp. 985-990
Author(s):  
V. Hernández ◽  
P. Hellín ◽  
J. Fenoll ◽  
M.V. Molina ◽  
I. Garrido ◽  
...  

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