scholarly journals Temperature but not the circadian clock determines nocturnal carbohydrate availability for growth in cereals

2018 ◽  
Author(s):  
Lukas M. Müller ◽  
Leonard Gol ◽  
Jong-Seong Jeon ◽  
Andreas P.M. Weber ◽  
Seth J. Davis ◽  
...  

AbstractThe circadian clock is considered a key target for crop improvement because it controls metabolism and growth in Arabidopsis. Here, we show that the clock gene EARLY FLOWERING 3 (ELF3) controls vegetative growth in Arabidopsis but not in the cereal crop barley. Growth in Arabidopsis is determined by the degradation of leaf starch reserves at night, which is controlled by ELF3. The vegetative growth of barley, however, is determined by the depletion of leaf sucrose stores through an exponential kinetics, presumably catalyzed by the vacuolar sucrose exporter SUCROSE TRANSPORTER 2 (SUT2). This process depends on the sucrose content and the nighttime temperature but not on ELF3. The regulation of starch degradation and sucrose depletion in barley ensures efficient growth at favorable temperature as stores become exhausted at dawn. On cool nights, however, only the starch degradation rate is compensated against low nighttime temperatures, whereas the sucrose depletion rate is reduced. This coincides with reduced biomass in barley but not in Arabidopsis after growth in consecutive cool nights. The sucrose depletion metabolism determines growth in the cereal crops barley, wheat, and rice but is not generally conserved in monocot species and is not a domestication-related trait. Therefore, the control of growth by endogenous (clock) versus external factors (temperature) is species-specific and depends on the predominant carbohydrate store. Our results give new insights into the physiology of growth in cereals and provide a basis for studying the genetics and evolution of different carbohydrate stores and their contribution to plant productivity and adaptation.Significance StatementThe circadian clock controls growth in the model plant Arabidopsis thaliana by regulating the starch degradation rate so that reserves last until dawn. This prevents nocturnal starvation until photosynthesis resumes. The cereal crops barley, wheat and rice, however, predominantly consume sucrose instead of starch as carbohydrate source. We find that carbohydrate supply from sucrose at night is regulated by enzyme kinetics and night-time temperature, but not the circadian clock. We postulate that the regulation of growth depends on the predominant carbohydrate store, where starch degradation is controlled by endogenous cues (clock) and sucrose depletion by external factors (temperature). These differences in the regulation of carbohydrate availability at night may have important implications for adapting crops yields to climate change.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Basavalingayya K. Swamy ◽  
Ravikumar Hosamani ◽  
Malarvizhi Sathasivam ◽  
S. S. Chandrashekhar ◽  
Uday G. Reddy ◽  
...  

AbstractHypergravity—an evolutionarily novel environment has been exploited to comprehend the response of living organisms including plants in the context of extra-terrestrial applications. Recently, researchers have shown that hypergravity induces desired phenotypic variability in seedlings. In the present study, we tested the utility of hypergravity as a novel tool in inducing reliable phenotype/s for potential terrestrial crop improvement applications. To investigate, bread wheat seeds (UAS-375 genotype) were subjected to hypergravity treatment (10×g for 12, and 24 h), and evaluated for seedling vigor and plant growth parameters in both laboratory and greenhouse conditions. It was also attempted to elucidate the associated biochemical and hormonal changes at different stages of vegetative growth. Resultant data revealed that hypergravity treatment (10×g for 12 h) significantly enhanced root length, root volume, and root biomass in response to hypergravity. The robust seedling growth phenotype may be attributed to increased alpha-amylase and TDH enzyme activities observed in seeds treated with hypergravity. Elevated total chlorophyll content and Rubisco (55 kDa) protein expression across different stages of vegetative growth in response to hypergravity may impart physiological benefits to wheat growth. Further, hypergravity elicited robust endogenous phytohormones dynamics in root signifying altered phenotype/s. Collectively, this study for the first time describes the utility of hypergravity as a novel tool in inducing reliable root phenotype that could be potentially exploited for improving wheat varieties for better water usage management.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Yanlei Yue ◽  
Ze Jiang ◽  
Enoch Sapey ◽  
Tingting Wu ◽  
Shi Sun ◽  
...  

Abstract Background In soybean, some circadian clock genes have been identified as loci for maturity traits. However, the effects of these genes on soybean circadian rhythmicity and their impacts on maturity are unclear. Results We used two geographically, phenotypically and genetically distinct cultivars, conventional juvenile Zhonghuang 24 (with functional J/GmELF3a, a homolog of the circadian clock indispensable component EARLY FLOWERING 3) and long juvenile Huaxia 3 (with dysfunctional j/Gmelf3a) to dissect the soybean circadian clock with time-series transcriptomal RNA-Seq analysis of unifoliate leaves on a day scale. The results showed that several known circadian clock components, including RVE1, GI, LUX and TOC1, phase differently in soybean than in Arabidopsis, demonstrating that the soybean circadian clock is obviously different from the canonical model in Arabidopsis. In contrast to the observation that ELF3 dysfunction results in clock arrhythmia in Arabidopsis, the circadian clock is conserved in soybean regardless of the functional status of J/GmELF3a. Soybean exhibits a circadian rhythmicity in both gene expression and alternative splicing. Genes can be grouped into six clusters, C1-C6, with different expression profiles. Many more genes are grouped into the night clusters (C4-C6) than in the day cluster (C2), showing that night is essential for gene expression and regulation. Moreover, soybean chromosomes are activated with a circadian rhythmicity, indicating that high-order chromosome structure might impact circadian rhythmicity. Interestingly, night time points were clustered in one group, while day time points were separated into two groups, morning and afternoon, demonstrating that morning and afternoon are representative of different environments for soybean growth and development. However, no genes were consistently differentially expressed over different time-points, indicating that it is necessary to perform a circadian rhythmicity analysis to more thoroughly dissect the function of a gene. Moreover, the analysis of the circadian rhythmicity of the GmFT family showed that GmELF3a might phase- and amplitude-modulate the GmFT family to regulate the juvenility and maturity traits of soybean. Conclusions These results and the resultant RNA-seq data should be helpful in understanding the soybean circadian clock and elucidating the connection between the circadian clock and soybean maturity.


2017 ◽  
Author(s):  
Charley J. Hubbard ◽  
Marcus T. Brock ◽  
Linda T.A. van Diepen ◽  
Loïs Maignien ◽  
Brent E. Ewers ◽  
...  

AbstractPlants alter chemical and physical properties of soil, and thereby influence rhizosphere microbial community structure. The structure of microbial communities may in turn affect plant performance. Yet, outside of simple systems with pairwise interacting partners, the plant genetic pathways that influence microbial community structure remain largely unknown, as are the performance feedbacks of microbial communities selected by the host plant genotype. We investigated the role of the plant circadian clock in shaping rhizosphere community structure and function. We performed 16S rRNA gene sequencing to characterize rhizosphere bacterial communities of Arabidopsis thaliana between day and night time points, and tested for differences in community structure between wild-type (Ws) vs. clock mutant (toc1-21, ztl-30) genotypes. We then characterized microbial community function, by growing wild-type plants in soils with an overstory history of Ws, toc1-21 or ztl-30 and measuring plant performance. We observed that rhizosphere community structure varied between day and night time points, and clock misfunction significantly altered rhizosphere communities. Finally, wild-type plants germinated earlier and were larger when inoculated with soils having an overstory history of wild-type in comparison to clock mutant genotypes. Our findings suggest the circadian clock of the plant host influences rhizosphere community structure and function.


2020 ◽  
Vol 21 (11) ◽  
pp. 4040 ◽  
Author(s):  
Waquar A. Ansari ◽  
Sonali U. Chandanshive ◽  
Vacha Bhatt ◽  
Altafhusain B. Nadaf ◽  
Sanskriti Vats ◽  
...  

Over the past decades, numerous efforts were made towards the improvement of cereal crops mostly employing traditional or molecular breeding approaches. The current scenario made it possible to efficiently explore molecular understanding by targeting different genes to achieve desirable plants. To provide guaranteed food security for the rising world population particularly under vulnerable climatic condition, development of high yielding stress tolerant crops is needed. In this regard, technologies upgradation in the field of genome editing looks promising. Clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 is a rapidly growing genome editing technique being effectively applied in different organisms, that includes both model and crop plants. In recent times CRISPR/Cas9 is being considered as a technology which revolutionized fundamental as well as applied research in plant breeding. Genome editing using CRISPR/Cas9 system has been successfully demonstrated in many cereal crops including rice, wheat, maize, and barley. Availability of whole genome sequence information for number of crops along with the advancement in genome-editing techniques provides several possibilities to achieve desirable traits. In this review, the options available for crop improvement by implementing CRISPR/Cas9 based genome-editing techniques with special emphasis on cereal crops have been summarized. Recent advances providing opportunities to simultaneously edit many target genes were also discussed. The review also addressed recent advancements enabling precise base editing and gene expression modifications. In addition, the article also highlighted limitations such as transformation efficiency, specific promoters and most importantly the ethical and regulatory issues related to commercial release of novel crop varieties developed through genome editing.


eLife ◽  
2013 ◽  
Vol 2 ◽  
Author(s):  
Antonio Scialdone ◽  
Sam T Mugford ◽  
Doreen Feike ◽  
Alastair Skeffington ◽  
Philippa Borrill ◽  
...  

Photosynthetic starch reserves that accumulate in Arabidopsis leaves during the day decrease approximately linearly with time at night to support metabolism and growth. We find that the rate of decrease is adjusted to accommodate variation in the time of onset of darkness and starch content, such that reserves last almost precisely until dawn. Generation of these dynamics therefore requires an arithmetic division computation between the starch content and expected time to dawn. We introduce two novel chemical kinetic models capable of implementing analog arithmetic division. Predictions from the models are successfully tested in plants perturbed by a night-time light period or by mutations in starch degradation pathways. Our experiments indicate which components of the starch degradation apparatus may be important for appropriate arithmetic division. Our results are potentially relevant for any biological system dependent on a food reserve for survival over a predictable time period.


2020 ◽  
Vol 2 (2) ◽  
pp. 28-34
Author(s):  
Arwan Sugiharto ◽  
Toga Pengihotan Napitupulu ◽  
Made Sudiana

Compared to other cereal crops, sorghum has a higher drought tolerance trait. However, efforts are needed to increase the productivity of sorghum, particularly in drought marginal land. One strategy to be implemented is the utilization of soil microorganisms formulated with biocarrier. Therefore, the aim of this study was to evaluate the influence of the fungal strain Aspergillus niger and Trichoderma harzianum formulated with compost and zeolite as biocarrier towards vegetative growth of sorghum. The field experiment was designed as a randomized block designed, factorial pattern with 4 replications. The first factor was selecting biocarrier, namely zeolite, compost, and a mixture of zeolite: compost (1:1). The second factor was the fungal inoculants, A. niger, and T. harzianum. The observed parameter was the growth profile of sorghum during vegetative growth, including stalk diameter and height. The results showed that the type of biocarrier, as well as the fungal strains did influence the growth of sorghum. The highest stalk diameter and height of sorghum were obtained after application of A. niger formulated with a mixture of zeolite: compost (1:1), with 17% and 41.2% higher than control, respectively. This condition shows that a mixture of zeolite and compost is seemingly able to create better micro-ecological conditions for fungal microbes to function effectively. Therefore, our findings suggested the addition of zeolite to compost for the application of biocarrier in the field experiment.


Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Kristen Solocinski ◽  
Xuerong Wen ◽  
Kit-Yan Cheng ◽  
Jeanette Lynch ◽  
Brian D Cain ◽  
...  

The circadian clock is important for maintaining rhythms in physiological functions including blood pressure (BP). Circadian disruption leads to increased disease risk. The clock has also been implicated in the maintenance of a normal dip in BP at night. In humans, non-dipping (night/day difference in BP<10%) is associated with an increased risk of cardiovascular and kidney disease. Dipping status can also be affected by salt intake and by hormones such as the mineralocorticoid aldosterone. The goal of this study was to determine the effects of a high salt (HS, 4% NaCl) diet plus mineralocorticoid (deoxycorticosterone pivalate (DOCP)) on BP regulation by the circadian clock protein Per1 in C57BL/6J mice. BP was monitored in conscious, unrestrained male mice by radiotelemetry and values are reported as mean arterial pressure (MAP) ± SEM. Under control conditions, MAP in male WT mice was 112.5 ± 1.08 mmHg during the night when mice are active and decreased to 102.1 ± 1.7 mmHg during the day, a “dip” in MAP of 9.2 ± 1.3%. Similarly, Per1 KO mice dip 14 ± 1.4%, with night time MAP of 119.8 ± .9 mmHg which decreased to 103 ± 1.4 mmHg during the day. On HS/DOCP, WT mice MAP decreased from 114.5 ± 1.1 mmHg to 101.5 ± 1.92 mmHg (night indicated by shaded bars in figure). This 11.4 ± 1.9% dip in WT mice was not significantly different from what was observed under control conditions. In contrast, Per1 KO mice display a significantly attenuated dip of 5.7 ± 1.4% with night time MAP of 125.3 ± 1.5 mmHg dropping to 118.1 ± 1 mmHg during the inactive day period (p<0.05). Thus, HS/DOCP treatment in Per1 KO mice leads to non-dipping hypertension. This is the first report of this phenotype in a single clock gene KO.


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