scholarly journals Knockout of the HvCKX1 or HvCKX3 Gene in Barley (Hordeum vulgare L.) by RNA-Guided Cas9 Nuclease Affects the Regulation of Cytokinin Metabolism and Root Morphology

Cells ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 782 ◽  
Author(s):  
Gasparis ◽  
Przyborowski ◽  
Kała ◽  
Nadolska-Orczyk

Barley is among four of the most important cereal crops with respect to global production. Increasing barley yields to desired levels can be achieved by the genetic manipulation of cytokinin content. Cytokinins are plant hormones that regulate many developmental processes and have a strong influence on grain yield. Cytokinin homeostasis is regulated by members of several multigene families. CKX genes encode the cytokinin oxidase/dehydrogenase enzyme, which catalyzes the irreversible degradation of cytokinin. Several recent studies have demonstrated that the RNAi-based silencing of CKX genes leads to increased grain yields in some crop species. To assess the possibility of increasing the grain yield of barley by knocking out CKX genes, we used an RNA-guided Cas9 system to generate ckx1 and ckx3 mutant lines with knockout mutations in the HvCKX1 and HvCKX3 genes, respectively. Homozygous, transgene-free mutant lines were subsequently selected and analyzed. A significant decrease in CKX enzyme activity was observed in the spikes of the ckx1 lines, while in the ckx3 lines, the activity remained at a similar level to that in the control plants. Despite these differences, no changes in grain yield were observed in either mutant line. In turn, differences in CKX activity in the roots between the ckx1 and ckx3 mutants were reflected via root morphology. The decreased CKX activity in the ckx1 lines corresponded to greater root length, increased surface area, and greater numbers of root hairs, while the increased CKX activity in the ckx3 mutants gave the opposite results. RNA-seq analysis of the spike and root transcriptomes revealed an altered regulation of genes controlling cytokinin metabolism and signaling, as well as other genes that are important during seed development, such as those that encode nutrient transporters. The observed changes suggest that the knockout of a single CKX gene in barley may be not sufficient for disrupting cytokinin homeostasis or increasing grain yields.

1982 ◽  
Vol 98 (2) ◽  
pp. 347-355 ◽  
Author(s):  
R. W. Daniels ◽  
M. B. Alcock ◽  
D. H. Scarisbrick

SUMMARYPre-anthesis stem reserve contribution to grain yield was assessed in two spring barley cultivars of contrasting height. It was greatest in the taller, but final grain yields were similar. Partitioning of total reserve capacity to various plant parts showed that the leaf and sheath below the peduncle were most important, followed by stem internodes which had increasing reserve capacity up to internode 4.It is suggested that stem reserves are valuable for yields commonly achieved in U.K. commercial practice.High grain yields were associated with large positive increases in stem dry weight after anthesis. This would indicate that the source capacity to boost yield is more than proportional to that required to fill the grain alone.


Soil Research ◽  
2010 ◽  
Vol 48 (2) ◽  
pp. 188 ◽  
Author(s):  
J. G. Nuttall ◽  
K. B. Hobson ◽  
M. Materne ◽  
D. B. Moody ◽  
R. Munns ◽  
...  

Subsoil physicochemical constraints such as primary salinity and high boron (B) can significantly reduce grain yields across wide areas of Australia. Financially viable amelioration options are limited for cropping systems on these soils, which has raised interest in ‘genetic solutions’. Increasing the tolerance of crops to high salinity and boron that typically co-exist within alkaline soils offers the potential for substantial yield benefits. To assess the contribution that genetic variation can make to crop yield, closely related genotypes differing in B and/or Na+ tolerance of bread and durum wheat, barley, and lentil were compared by growing the different lines in intact soil cores of 2 Calcarosol profiles differing in level of subsoil constraints (‘hostile’/’benign’). The hostile profile had salinity increasing to EC1 : 5 ~1.2 dS/m and B ~18 mg/kg to 0.60 m, whereas in the benign soil EC1 : 5 did not exceed ~0.6 dS/m and B ~11 mg/kg. Grain yields were significantly less on the hostile soil than the benign soil for barley (34%), bread wheat (20%), durum wheat (31%), and lentil (38%). Accumulation of B in shoots was significantly lower on the hostile soil across all crop species, indicating high sodium within the soil was associated with inhibited uptake of B in plants. In contrast, accumulation of Na+ was greater for all cereal crops in the hostile soil compared with the benign soil. Lentil plants with reputed sodium tolerance (CIPAL415) produced a significant yield benefit on both the benign and hostile soil over the commercial line, Nugget. The lentil line with combined Na+ and B tolerance (02-355L*03Hs005) also produced an additional yield increase over CIPAL415 on the hostile soil; however, yield was equivalent on the benign soil. For durum wheat, 2 genotypes differing in Na+ tolerance, containing either the Nax1 or Nax2 genes, accumulated less sodium in the straw than the parent cv. Tamaroi within the hostile soil; however, this did not translate to a yield advantage. For barley, there was no difference in either grain yield or B uptake in either the grain or straw between the B-tolerance line 03_007D_087 and its parent cv. Buloke. Similarly, there was no difference in either grain yield or B uptake between the bread wheat Schomburgk and its B-tolerant near-isogenic line BT-Schomburgk. This study suggests that of the cereal lines tested, there was no obvious benefit in lines with potentially improved tolerance for a single, specific subsoil constraint on alkaline soils where multiple potential constraints exist. In contrast, in lentils, incorporating tolerance to Na+ and B did show promise for increased adaptation to soils with subsoil constraints.


1979 ◽  
Vol 59 (4) ◽  
pp. 981-989
Author(s):  
J. M. DESCHENES ◽  
J. P. DUBUC

The effect of four rates (9–36 t/ha) of sheep manure applied in the fall was compared to conventional inorganic fertilization (49 kg of N, 60 kg of P2O5 and 60 kg of K2O/ha) applied at seeding on three species of cereals. Weed populations, lodging and grain yields were recorded on oats (Avena sativa L.), barley (Hordeum vulgare L.) and wheat (Triticum aestivum L.) from 1976 to 1978 on the St-André sandy loam and in 1977 and 1978 on the Kamouraska clay. The manure applied came from sheep fed entirely with hay silage. The various rates of sheep manure had no effect on weed population since no significant difference has been observed between the organic and inorganic fertilization. Lodging did not occur in any of the plots, irrespective of the soil type, during the 3 yr of the experiment. For the two soil types, the grain yields of oats, barley and wheat were usually higher on plots that received 27–36 t/ha of sheep manure than on plots that received inorganic fertilizer. The rates of 9 and 18 t/ha of manure resulted in grain yields significantly lower. An application on all plots of 15 kg/ha of inorganic nitrogen in the spring of 1978 has sensibly increased the grain yield. These results suggest that the fall spreading and the incorporation into the soil of 36 t/ha of sheep manure followed by an application of about 15 kg/ha of inorganic nitrogen in the spring provide a very satisfactory grain yield and do not increase the incidence of lodging and weed infestation.


Author(s):  
Om Prakash Yadav ◽  
A. K. Razdan ◽  
Bupesh Kumar ◽  
Praveen Singh ◽  
Anjani K. Singh

Genotype by environment interaction (GEI) of 18 barley varieties was assessed during two successive rabi crop seasons so as to identify high yielding and stable barley varieties. AMMI analysis showed that genotypes (G), environment (E) and GEI accounted for 1672.35, 78.25 and 20.51 of total variance, respectively. Partitioning of sum of squares due to GEI revealed significance of interaction principal component axis IPCA1 only On the basis of AMMI biplot analysis DWRB 137 (41.03qha–1), RD 2715 (32.54qha–1), BH 902 (37.53qha–1) and RD 2907 (33.29qha–1) exhibited grain yield superiority of 64.45, 30.42, 50.42 and 33.42 per cent, respectively over farmers’ recycled variety (24.43qha–1).


Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 885
Author(s):  
Pooja Tripathi ◽  
Sangita Subedi ◽  
Abdul Latif Khan ◽  
Yong-Suk Chung ◽  
Yoonha Kim

Roots play an essential function in the plant life cycle, as they utilize water and essential nutrients to promote growth and plant productivity. In particular, root morphology characteristics (such as length, diameter, hairs, and lateral growth) and the architecture of the root system (spatial configuration in soil, shape, and structure) are the key elements that ensure growth and a fine-tuned response to stressful conditions. Silicon (Si) is a ubiquitous element in soil, and it can affect a wide range of physiological processes occurring in the rhizosphere of various crop species. Studies have shown that Si significantly and positively enhances root morphological traits, including root length in rice, soybean, barley, sorghum, mustard, alfalfa, ginseng, and wheat. The analysis of these morphological traits using conventional methods is particularly challenging. Currently, image analysis methods based on advanced machine learning technologies allowed researchers to screen numerous samples at the same time considering multiple features, and to investigate root functions after the application of Si. These methods include root scanning, endoscopy, two-dimensional, and three-dimensional imaging, which can measure Si uptake, translocation and root morphological traits. Small variations in root morphology and architecture can reveal different positive impacts of Si on the root system of crops, with or without exposure to stressful environmental conditions. This review comprehensively illustrates the influences of Si on root morphology and root architecture in various crop species. Furthermore, it includes recommendations in regard to advanced methods and strategies to be employed to maintain sustainable plant growth rates and crop production in the currently predicted global climate change scenarios.


1977 ◽  
Vol 57 (2) ◽  
pp. 157-164 ◽  
Author(s):  
D. C. PENNEY ◽  
M. NYBORG ◽  
P. B. HOYT ◽  
W. A. RICE ◽  
B. SIEMENS ◽  
...  

The amount of cultivated acid soil in Alberta and northeastern British Columbia was estimated from pH values of farm samples analyzed by the Alberta Soil Testing Laboratory, and the effect of soil acidity on crops was assessed from field experiments on 28 typical acid soils. The field experiments consisted of two cultivars of barley (Hordeum vulgare L.) and one cultivar each of rapeseed (Brassica campestris L.), red clover (Trifolium pratense L.) and alfalfa (Medicago sativa L.) grown with and without lime for 2 yr. There are about 30,000 ha of soils with a pH of 5.0 or less where soil acidity seriously restricts yields of all four crop species. There are approximately 300,000 ha with a soil pH of 5.1–5.5 where liming will on the average increase yields of alfalfa by 100%, yields of barley by 10–15%, and yields of rapeseed and red clover by 5–10%. There are a further 1,600,000 ha where soil pH ranges from 5.6 to 6.0 and liming will increase yields of alfalfa by approximately 50% and yields of barley, rapeseed and red clover by at least 4–5%.


2016 ◽  
Vol 96 (3) ◽  
pp. 367-370
Author(s):  
Thin Meiw Choo ◽  
Allen G. Xue ◽  
Richard A. Martin

AAC Vitality is a six-row spring feed barley (Hordeum vulgare L.) cultivar developed by the Eastern Cereal and Oilseed Research Centre, Agriculture and Agri-Food Canada. AAC Vitality had high grain yield, good resistance to lodging, and good resistance to straw break. It was late in heading and maturity. Its seed color was bright. AAC Vitality was moderately resistant to net blotch and spot blotch. AAC Vitality performs well in Ontario.


2021 ◽  
Author(s):  
Mekides Woldegiorgis Gardi ◽  
Bettina I.G Haussmann ◽  
Waqas Ahmed Malik ◽  
Petra Högy

Abstract AimsThe general aim of this meta-analysis is to synthesize and summarise the mean response of barley yield variables to elevated CO2 (eCO2) and its interaction with temperature and N fertilization. Methods The present study quantitatively synthesized the response of barley to eCO2 and its interaction with temperature, and Nitrogen (N). A meta-analysis procedure was used to analyse five yield variables of barley extracted from 76 articles to determine the effect size and the magnitude in relation to eCO2 and its interaction with temperature and N. Results CO2 enrichment increased biomass (23.8%), grain number (24.8%), grain yield (27.4%), and thousand-grain weight (5.6%). However, responses to eCO2 were affected by genotype, additional stress, and experimental conditions. In comparison, genotype “Anakin” shows the highest response of biomass (47.1%), while “Genebank accessions” had a higher grain number (46.1%) and grain yield (57.1%) under eCO2. The maximal enhancement of barley yield was observed when plants grow under a combination of eCO2 and higher nitrogen fertilizer (>100 kg ha-1). Nevertheless, biomass (-12%), and grain yield (-17%) responses were lower when eCO2 is combined with high temperature (>25 °C). It was further noted the response of barley yield to eCO2 was higher in the growth chamber than in other CO2 exposure methods. Moreover, comparing pot-rooted versus field-rooted barley plants, a higher response of biomass and grain yield was observed for pot-rooted plants. ConclusionsOverall, results suggest that the maximal barley production under eCO2 will be obtained in combination with high nitrogen fertilizer and optimal temperature (21-25 °C).


2017 ◽  
Vol 155 (9) ◽  
pp. 1394-1406 ◽  
Author(s):  
X. M. MAO ◽  
W. W. ZHONG ◽  
X. Y. WANG ◽  
X. B. ZHOU

SUMMARYThe production of winter wheat (Triticum aestivum L.) is affected by crop population structures and field microclimates. This 3-year study assessed the effect of different precision planting patterns and irrigation conditions on relative humidity (RH), air and soil temperature within the canopy, intercepted photosynthetically active radiation (iPAR), evapotranspiration (ET), water productivity (WP) and grain yields. Field experiments were conducted from 2011 to 2014 on a two-factor split-plot design with three replicates. The experiments involved three precision planting patterns (single row, alternating single and twin rows [hereafter ‘single–twin’] and twin row) and three irrigation treatments (0 mm (I0), 90 mm (I90) and 180 mm (I180)). Planting patterns and irrigation treatments exerted a significant effect on RH, air and soil temperature, iPAR, ET, WP and grain yield. The lowest RH and iPAR levels were detected in the single row pattern. When the irrigation treatment was identical, the highest soil and air temperatures were detected in the single row pattern, followed by the single–twin row and twin row patterns. Compared with the single row, the single–twin and twin row patterns increased ET by 0·3 and 1·4, WP by 4·7 and 5·7% and yields by 6·0 and 7·9%, respectively. Compared with I0, the I90 and I180 irrigation treatments increased ET by 0·3 and 1·4%, and WP by 4·7 and 5·7%, respectively. The grain yields of the twin row pattern were 5·8 and 1·7% higher than those of the single row and single–twin row patterns, respectively. Compared with I0, I90 increased yield by 19·3%. The twin row pattern improved crop structure and farmland microclimate by increasing RH and iPAR, and reducing soil and air temperatures, thus increasing grain yield. These results indicated that a twin row pattern effectively improved grain yield at I0. On the basis of iPAR, WP and grain yield, it was concluded that a twin row pattern combined with an I90 irrigation treatment provided optimal cropping conditions for the North China plain.


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