scholarly journals Amylopectin Chain Length Dynamics and Activity Signatures of Key Carbon Metabolic Enzymes Highlight Early Maturation as Culprit for Yield Reduction of Barley Endosperm Starch after Heat Stress

2019 ◽  
Vol 60 (12) ◽  
pp. 2692-2706 ◽  
Author(s):  
Jose Antonio Cuesta-Seijo ◽  
Alice Jara De Porcellinis ◽  
Angela H�rdum Valente ◽  
Alexander Striebeck ◽  
Cynthia Voss ◽  
...  

Abstract Abiotic environmental stresses have a negative impact on the yield and quality of crops. Understanding these stresses is an essential enabler for mitigating breeding strategies and it becomes more important as the frequency of extreme weather conditions increases due to climate change. This study analyses the response of barley (Hordeum vulgare L.) to a heat wave during grain filling in three distinct stages: the heat wave itself, the return to a normal temperature regime, and the process of maturation and desiccation. The properties and structure of the starch produced were followed throughout the maturational stages. Furthermore, the key enzymes involved in the carbohydrate supply to the grain were monitored. We observed differences in starch structure with well-separated effects because of heat stress and during senescence. Heat stress produced marked effects on sucrolytic enzymes in source and sink tissues. Early cessation of plant development as an indirect consequence of the heat wave was identified as the major contributor to final yield loss from the stress, highlighting the importance for functional stay-green traits for the development of heat-resistant cereals.

2019 ◽  
Vol 71 (2) ◽  
pp. 543-554 ◽  
Author(s):  
Mostafa Abdelrahman ◽  
David J Burritt ◽  
Aarti Gupta ◽  
Hisashi Tsujimoto ◽  
Lam-Son Phan Tran

Abstract Crops such as wheat (Triticum spp.) are predicted to face more frequent exposures to heat stress as a result of climate change. Increasing the yield and sustainability of yield under such stressful conditions has long been a major target of wheat breeding, and this goal is becoming increasingly urgent as the global population increases. Exposure of wheat plants in their reproductive or grain-filling stage to high temperature affects the duration and rate of grain filling, and hence has a negative impact on wheat productivity. Therefore, understanding the plasticity of the response to heat stress that exists between wheat genotypes, especially in source–sink relationships at the reproductive and grain-filling stages, is critical for the selection of germplasm that can maintain high yields under heat stress. A broad understanding of metabolic dynamics and the relationships between metabolism and heat tolerance is required in order to achieve this goal. Here, we review the current literature concerning the effects of heat stress on sink–source relationships in a wide range of wheat genotypes, and highlight the current metabolomic approaches that are used to investigate high temperature responses in wheat.


Author(s):  
V. Rajeswari ◽  
D. Vijayalakshmi ◽  
S. Srinivasan ◽  
R. Swarnapriya ◽  
S. Varanavasiappan ◽  
...  

Drought spells and heat stress have become quite common and agricultural production would experience a lag in near future. The combined effect of heat and drought stress is expected to cause negative impact on crop growth. Hence, an experiment was framed to assess the morphological and photosynthetic characters of chilli under combined drought and heat stress. Three different genotypes of chilli viz., K1, TNAU chilli hybrid CO 1, Ramanathapuram gundu were subjected to seven drought and temperature treatments. The experiment was designed in factorial completely randomized design (FCRD) at temperature controlled Open Top Chambers (OTC) and drought stress was gravimetically assesed. The results showed that, morphology and photosynthetic characters were affected irrespective of genotypes. The maximum reduction in plant height and leaf area was observed when plants were grown under 40% pot capacity and temperature of + 5°C from the ambient condition. The study also revealed that, the reduction of gas exchange parameters at 40% PC and A + 5°C with yield reduction of almost 76 per cent irrespective of genotypes. Stress treatments reduced the fruit length, fruit diameter compared to control in all genotypes. Stress Tolerence Index was calculated to study the physiological basis under combined drought and heat stress. The optimum level of stress by STI of 0.501 in 60% PC and A+ 3°C was standardized to study the basic physiological functions of chilli.


2021 ◽  
Vol 12 (1) ◽  
pp. 059-063
Author(s):  
D. Dev Kumar ◽  
◽  
V. Padma ◽  
H. S. Talwar ◽  
Farzana Jabeen ◽  
...  

An experiment was conducted during rabi 2012-13 at research farm of Indian Institute of Millet Research (IIMR), Rajendranagar, Hyderabad, Telengana State, India. The experiment was laid out in a split plot design, replicated thrice, with 10 Sorghum genotypes as main treatment Well-watered (WW) and Water-stress (WS) conditions) to examine the potential of Sorghum genotypes to adapt to the post flowering drought. 10 genotypes are sub-treatments CRS 4, CRS 19, CRS 20, PEC 17, CSV 18, M 35-1, Phule chitra, Phule moulee, EP 57 and CRS 1). Among the four stages viz., 10, 20, 30 and 40 days after flowering (DAF), the GLAR (stay green trait) at 10 DAF had a positive and higher significant correlation with grain yield (r=0.66). So, GLAR at 10 DAF is most appropriate stage to screen for post flowering drought tolerance. Among the yield components, number of grains per panicle, grain weight panicle-1 and harvest index (HI) are significantly and positively correlated with grain yield and therefore it can be ascribed that the genotypes, which partitioned more assimilates into economic parts and in which grain filling is high, recorded more grain yield. The overall yield reduction due to moisture stress during the post flowering drought was 10% and it ranged between 8-12% among the genotypes. This indicates that the genotypes used in the present study are relatively drought tolerant. The genotypes CSV 18 and Phule moulee registered least yield reduction (8%) in grain yield due to post flowering drought followed by PEC 17 and M 35-1 which registered 9% yield reduction. However, the overall grain yield of PEC 17 and M 35-1 was more than CSV 18 and Phule moulee even under moisture stress conditions.


2019 ◽  
Vol 20 (23) ◽  
pp. 5837 ◽  
Author(s):  
Kamal ◽  
Alnor Gorafi ◽  
Abdelrahman ◽  
Abdellatef ◽  
Tsujimoto

The yield losses in cereal crops because of abiotic stress and the expected huge losses from climate change indicate our urgent need for useful traits to achieve food security. The stay-green (SG) is a secondary trait that enables crop plants to maintain their green leaves and photosynthesis capacity for a longer time after anthesis, especially under drought and heat stress conditions. Thus, SG plants have longer grain-filling period and subsequently higher yield than non-SG. SG trait was recognized as a superior characteristic for commercially bred cereal selection to overcome the current yield stagnation in alliance with yield adaptability and stability. Breeding for functional SG has contributed in improving crop yields, particularly when it is combined with other useful traits. Thus, elucidating the molecular and physiological mechanisms associated with SG trait is maybe the key to defeating the stagnation in productivity associated with adaptation to environmental stress. This review discusses the recent advances in SG as a crucial trait for genetic improvement of the five major cereal crops, sorghum, wheat, rice, maize, and barley with particular emphasis on the physiological consequences of SG trait. Finally, we provided perspectives on future directions for SG research that addresses present and future global challenges.


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.


2021 ◽  
Vol 264 ◽  
pp. 108087
Author(s):  
HyeonSeok Lee ◽  
MyoungGoo Choi ◽  
WoonHa Hwang ◽  
JaeHyeok Jeong ◽  
SeoYeong Yang ◽  
...  

Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 43
Author(s):  
Adeel Khan ◽  
Munir Ahmad ◽  
Mukhtar Ahmed ◽  
M. Iftikhar Hussain

Temperature across the globe is increasing continuously at the rate of 0.15–0.17 °C per decade since the industrial revolution. It is influencing agricultural crop productivity. Therefore, thermotolerance strategies are needed to have sustainability in crop yield under higher temperature. However, improving thermotolerance in the crop is a challenging task for crop scientists. Therefore, this review work was conducted with the aim of providing information on the wheat response in three research areas, i.e., physiology, breeding, and advances in genetics, which could assist the researchers in improving thermotolerance. The optimum temperature for wheat growth at the heading, anthesis, and grain filling duration is 16 ± 2.3 °C, 23 ± 1.75 °C, and 26 ± 1.53 °C, respectively. The high temperature adversely influences the crop phenology, growth, and development. The pre-anthesis high temperature retards the pollen viability, seed formation, and embryo development. The post-anthesis high temperature declines the starch granules accumulation, stem reserve carbohydrates, and translocation of photosynthates into grains. A high temperature above 40 °C inhibits the photosynthesis by damaging the photosystem-II, electron transport chain, and photosystem-I. Our review work highlighted that genotypes which can maintain a higher accumulation of proline, glycine betaine, expression of heat shock proteins, stay green and antioxidant enzymes activity viz., catalase, peroxidase, super oxide dismutase, and glutathione reductase can tolerate high temperature efficiently through sustaining cellular physiology. Similarly, the pre-anthesis acclimation with heat treatment, inorganic fertilizer such as nitrogen, potassium nitrate and potassium chloride, mulches with rice husk, early sowing, presoaking of a 6.6 mM solution of thiourea, foliar application of 50 ppm dithiothreitol, 10 mg per kg of silicon at heading and zinc ameliorate the crop against the high temperature. Finally, it has been suggested that modern genomics and omics techniques should be used to develop thermotolerance in wheat.


2021 ◽  
Vol 19 (1) ◽  
pp. 74-89
Author(s):  
Amandeep Kaur ◽  
Parveen Chhuneja ◽  
Puja Srivastava ◽  
Kuldeep Singh ◽  
Satinder Kaur

AbstractAddressing the impact of heat stress during flowering and grain filling is critical to sustaining wheat productivity to meet a steadily increasing demand from a rapidly growing world population. Crop wild progenitor species of wheat possess a wealth of genetic diversity for several biotic and abiotic stresses, and morphological traits and can serve as valuable donors. The transfer of useful variation from the diploid progenitor, Aegilops tauschii, to hexaploid wheat can be done through the generation of synthetic hexaploid wheat (SHW). The present study targeted the identification of potential primary SHWs to introduce new genetic variability for heat stress tolerance. Selected SHWs were screened for different yield-associated traits along with three advanced breeding lines and durum parents as checks for assessing terminal heat stress tolerance under timely and late sown conditions for two consecutive seasons. Heat tolerance index based on the number of productive tillers and thousand grain weight indicated that three synthetics, syn9809 (64.32, 78.80), syn14128 (50.30, 78.28) and syn14135 (58.16, 76.03), were able to endure terminal heat stress better than other SHWs as well as checks. One of these synthetics, syn14128, recorded a minimum reduction in thousand kernel weight (21%), chlorophyll content (2.56%), grain width (1.07%) despite minimum grain-filling duration (36.15 d) and has been selected as a potential candidate for introducing the terminal heat stress tolerance in wheat breeding programmes. Breeding efforts using these candidate donors will help develop lines with a higher potential to express the desired heat stress-tolerant phenotype under field conditions.


2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Dong Won Jeon ◽  
Jae-Ryoung Park ◽  
Yoon-Hee Jang ◽  
Eun-Gyeong Kim ◽  
Taehun Ryu ◽  
...  

Abstract Background The drought environment occurs frequently due to the unpredictable future climate change, and drought has a direct negative impact on crops, such as yield reduction. Drought events are random, frequent, and persistent. Molecular breeding can be used to create drought-tolerant food crops, but the safety of genetically modified (GM) plants must be demonstrated before they can be adopted. In this research, the environmental risk of drought-tolerant GM rice was explored by assessing phenotype and gene flow. Drought resistance genes CaMsrB2 inserted HV8 and HV23 were used as GM rice to analyze the possibility of various agricultural traits and gene flow along with non-GM rice. Results When the traits 1000-grain weight, grain length/width, and yield, were compared with GM rice and non-GM rice, all agricultural traits of GM rice and non-GM rice were the same. In addition, when the germination rate, viviparous germination rate, pulling strength, and bending strength were compared to analyze the possibility of weediness, all characteristic values of GM rice and non-GM rice were the same. Protein, amylose, and moisture, the major nutritional elements of rice, were also the same. Conclusions The results of this research are that GM rice and non-GM rice were the same in all major agricultural traits except for the newly assigned characteristics, and no gene mobility occurred. Therefore, GM rice can be used as a means to solve the food problem in response to the unpredictable era of climate change in the future.


Author(s):  
Małgorzata Pawlak ◽  
Michał Kuźniar ◽  
Andrzej R. Majka

The present-day world is characterized by the intense development of air transport. However, along with it, significant problems appear. Among these problems, the most important are those relating to safety and negative impact of air transport on the environment. Air transport efficiency and profitability issues, although not critical, must also be taken into account because they decide about the intensity of development of this branch of transport. There are currently two large programs in Europe oriented at improving safety, environmental, and efficiency indicators. These are SESAR 2020 and Clean Sky 2, being a continuation of previous ones. One of the ways to reduce negative impact of air transport on the environment and improve its efficiency is to reduce fuel consumption and pollutants emissions resulting from fuel combustion. To find solutions with the abovementioned features, it is necessary to have sufficiently accurate models to estimate the amount of fuel consumed and the amount of pollutants emitted. Developing a sufficiently accurate model to determine fuel consumption and pollutants emission was performed. Due to the specificity of the missions carried out by passenger aircraft, the focus was on the cruise stage when aircraft flies at a constant altitude with a constant air speed. The result of the analysis was the development of methodology for fuel consumption and emission of main pollutants in cruise conditions. Specific fuel consumption is calculated for the thrust required for horizontal flight at cruising altitude. Emission indexes for CO, NOx, HC, and CO2 for the cruise have been determined based on known indexes for the landing and take-off cycle phase, after applying appropriate corrections. An illustration of the application of the developed methodology was the optimization of a medium-sized transport aircraft trajectory on a selected connection to determine a trajectory characterized by a minimum emission value taking into account weather conditions.


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