scholarly journals Autophagy is responsible for the accumulation of proteogenic dipeptides in response to heat stress in Arabidopsis thaliana

2020 ◽  
Author(s):  
Venkatesh P. Thirumalaikumar ◽  
Mateusz Wagner ◽  
Salma Balazadeh ◽  
Aleksandra Skirycz

AbstractProteogenic dipeptides are intermediates of proteolysis as well as an emerging class of small-molecule regulators with diverse and often dipeptide-specific functions. Herein, prompted by differential accumulation of dipeptides in a high-density Arabidopsis thaliana time-course stress experiment, we decided to pursue an identity of the proteolytic pathway responsible for the buildup of dipeptides under heat conditions. By querying dipeptide accumulation versus available transcript data, autophagy emerged as a top hit. To examine whether autophagy indeed contributes to the accumulation of dipeptides measured in response to heat stress, we characterized the loss-of-function mutants of crucial autophagy proteins to test whether interfering with autophagy would affect dipeptide accumulation in response to the heat treatment. This was indeed the case. This work implicates the involvement of autophagy in the accumulation of proteogenic dipeptides in response to heat stress in Arabidopsis.

Plants ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 323 ◽  
Author(s):  
Imene Toumi ◽  
Marianthi G. Pagoulatou ◽  
Theoni Margaritopoulou ◽  
Dimitra Milioni ◽  
Kalliopi A. Roubelakis-Angelakis

The chaperones, heat shock proteins (HSPs), stabilize proteins to minimize proteotoxic stress, especially during heat stress (HS) and polyamine (PA) oxidases (PAOs) participate in the modulation of the cellular homeostasis of PAs and reactive oxygen species (ROS). An interesting interaction of HSP90s and PAOs was revealed in Arabidopsis thaliana by using the pLFY:HSP90RNAi line against the four AtHSP90 genes encoding cytosolic proteins, the T-DNA Athsp90-1 and Athsp90-4 insertional mutants, the Atpao3 mutant and pharmacological inhibitors of HSP90s and PAOs. Silencing of all cytosolic HSP90 genes resulted in several-fold higher levels of soluble spermidine (S-Spd), acetylated Spd (N8-acetyl-Spd) and acetylated spermine (N1-acetyl-Spm) in the transgenic Arabidopsis thaliana leaves. Heat shock induced increase of soluble-PAs (S-PAs) and soluble hydrolyzed-PAs (SH-PAs), especially of SH-Spm, and more importantly of acetylated Spd and Spm. The silencing of HSP90 genes or pharmacological inhibition of the HSP90 proteins by the specific inhibitor radicicol, under HS stimulatory conditions, resulted in a further increase of PA titers, N8-acetyl-Spd and N1-acetyl-Spm, and also stimulated the expression of PAO genes. The increased PA titers and PAO enzymatic activity resulted in a profound increase of PAO-derived hydrogen peroxide (H2O2) levels, which was terminated by the addition of the PAO-specific inhibitor guazatine. Interestingly, the loss-of-function Atpao3 mutant exhibited increased mRNA levels of selected AtHSP90 genes. Taken together, the results herein reveal a novel function of HSP90 and suggest that HSP90s and PAOs cross-talk to orchestrate PA acetylation, oxidation, and PA/H2O2 homeostasis.


Forests ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 656 ◽  
Author(s):  
Qinsong Liu ◽  
Ramesh R. Vetukuri ◽  
Wenjuan Xu ◽  
Xiao Xu

The dove tree (Davidia involucrata Baill.), a tertiary relic species, is adapted to cool climates. With the progression of global warming, high-temperature stress has become the primary environmental factor restricting geographic distribution, ex situ conservation, and landscape application for D. involucrata resources. However, the detailed molecular events underlying D. involucrata responses to heat stress are poorly understood. Here, we conducted RNA-Seq-based gene expression profiling in D. involucrata seedlings during the time course of a 42 °C heat treatment (0, 1, 6, and 12 h). After de novo assembly, we obtained 138,923 unigenes, of which 69,743 were annotated in public databases. Furthermore, 19,532, 20,497 and 27,716 differentially expressed genes (DEGs) were identified after 1 h (HS1), 6 h (HS6), and 12 h (HS12) of heat treatment in comparison to 0 h (HS0), respectively. Based on a KEGG enrichment analysis, the two pathways “protein processing in endoplasmic reticulum” and “plant hormone signal transduction” are hypothesized to play vital roles during heat response in D. involucrata, and their potential interactions during heat stress are also discussed. In addition, 32 genes encoding putative heat shock transcription factors (Hsfs) were found to be associated with the response of D. involucrata to heat stress. Finally, the expression patterns of eight heat-responsive genes derived from qRT-PCR were in agreement with their transcript level alterations, as determined by a transcriptome analysis. Taken together, our transcriptomic data provide the first comprehensive transcriptional profile affected by heat stress in D. involucrata, which will facilitate further studies on the improvement of heat tolerance in this rare and endangered species.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sherzod Nigmatullayevich Rajametov ◽  
Eun Young Yang ◽  
Myeong Cheoul Cho ◽  
Soo Young Chae ◽  
Hyo Bong Jeong ◽  
...  

AbstractUnderstanding the mechanism for heat tolerance is important for the hot pepper breeding program to develop heat-tolerant cultivars in changing climate. This study was conducted to investigate physiological and biochemical parameters related to heat tolerance and to determine leaf heat damage levels critical for selecting heat-tolerant genotypes. Seedlings of two commercial cultivars, heat-tolerant ‘NW Bigarim’ (NB) and susceptible ‘Chyung Yang’ (CY), were grown in 42 °C for ten days. Photosynthesis, electrolyte conductivity, proline content were measured among seedlings during heat treatment. Photosynthetic rate was significantly reduced in ‘CY’ but not in ‘NB’ seedlings in 42 °C. Stomatal conductivity and transpiration rate was significantly higher in ‘NB’ than ‘CY’. Proline content was also significantly higher in ‘NB’. After heat treatment, leaf heat damages were determined as 0, 25, 50 and 75% and plants with different leaf heat damages were moved to a glasshouse (30–32/22–24 °C in day/night). The growth and developmental parameters were investigated until 70 days. ‘NB’ was significantly affected by leaf heat damages only in fruit yield while ‘CY’ was in fruit set, number and yield. ‘NB’ showed fast recovery after heat stress compared to ‘CY’. These results suggest that constant photosynthetic rate via increased transpiration rate as well as high proline content in heat stress condition confer faster recovery from heat damage of heat-tolerant cultivars in seedlings stages.


Author(s):  
Mahmoud Hussien Abou-Deif ◽  
Mohamed Abdel-Salam Rashed ◽  
Kamal Mohamed Khalil ◽  
Fatma El-Sayed Mahmoud

Abstract Background Maize is one of the important cereal food crops in the world. High temperature stress causes adverse influence on plant growth. When plants are exposed to high temperatures, they produce heat shock proteins (HSPs), which may impart a generalized role in tolerance to heat stress. Proteome analysis was performed in plant to assess the changes in protein types and their expression levels under abiotic stress. The purpose of the study is to explore which proteins are involved in the response of the maize plant to heat shock treatment. Results We investigated the responses of abundant proteins of maize leaves, in an Egyptian inbred line of maize “K1”, upon heat stress through two-dimensional electrophoresis (2-DE) on samples of maize leaf proteome. 2-DE technique was used to recognize heat-responsive protein spots using Coomassie Brilliant Blue (CBB) and silver staining. In 2-D analysis of proteins from plants treated at 45 °C for 2 h, the results manifested 59 protein spots (4.3%) which were reproducibly detected as new spots where did not present in the control. In 2D for treated plants for 4 h, 104 protein spots (7.7%) were expressed only under heat stress. Quantification of spot intensities derived from heat treatment showed that twenty protein spots revealed clear differences between the control and the two heat treatments. Nine spots appeared with more intensity after heat treatments than the control, while four spots appeared only after heat treatments. Five spots were clearly induced after heat treatment either at 2 h or 4 h and were chosen for more analysis by LC-MSMS. They were identified as ATPase beta subunit, HSP26, HSP16.9, and unknown HSP/Chaperonin. Conclusion The results revealed that the expressive level of the four heat shock proteins that were detected in this study plays important roles to avoid heat stress in maize plants.


2010 ◽  
Vol 48 (8) ◽  
pp. 697-702 ◽  
Author(s):  
Nisreen A. AL-Quraan ◽  
Robert D. Locy ◽  
Narendra K. Singh

Author(s):  
Maurizio Iovane ◽  
Giovanna Aronne

AbstractMany crop species are cultivated to produce seeds and/or fruits and therefore need reproductive success to occur. Previous studies proved that high temperature on mature pollen at anther dehiscence reduce viability and germinability therefore decreasing crop productivity. We hypothesized that high temperature might affect pollen functionality even if the heat treatment is exerted only during the microsporogenesis. Experimental data on Solanum lycopersicum ‘Micro-Tom’ confirmed our hypothesis. Microsporogenesis successfully occurred at both high (30 °C) and optimal (22 °C) temperature. After the anthesis, viability and germinability of the pollen developed at optimal temperature gradually decreased and the reduction was slightly higher when pollen was incubated at 30 °C. Conversely, temperature effect was eagerly enhanced in pollen developed at high temperature. In this case, a drastic reduction of viability and a drop-off to zero of germinability occurred not only when pollen was incubated at 30 °C but also at 22 °C. Further ontogenetic analyses disclosed that high temperature significantly speeded-up the microsporogenesis and the early microgametogenesis (from vacuolated stage to bi-cellular pollen); therefore, gametophytes result already senescent at flower anthesis. Our work contributes to unravel the effects of heat stress on pollen revealing that high temperature conditions during microsporogenesis prime a fatal shortening of the male gametophyte lifespan.


Sign in / Sign up

Export Citation Format

Share Document