The regulation of root growth in response to phosphorus deficiency mediated by phytohormones in a Tibetan wild barley accession

2016 ◽  
Vol 38 (4) ◽  
Author(s):  
Umme Aktari Nadira ◽  
Imrul Mosaddek Ahmed ◽  
Feibo Wu ◽  
Guoping Zhang
2016 ◽  
Vol 198 ◽  
pp. 10-22 ◽  
Author(s):  
Umme Aktari Nadira ◽  
Imrul Mosaddek Ahmed ◽  
Jianbin Zeng ◽  
Feibo Wu ◽  
Guoping Zhang

Genome ◽  
2009 ◽  
Vol 52 (10) ◽  
pp. 849-861 ◽  
Author(s):  
Xue Gong ◽  
Sharon Westcott ◽  
Chengdao Li ◽  
Guijun Yan ◽  
Reg Lance ◽  
...  

Fifty-two SSR markers were used to evaluate the genetic diversity of 33 Qinghai-Tibetan wild barley accessions, 56 landraces collected primarily from other parts of China, and 1 Israeli wild barley accession. At the 52 SSR loci, 206 alleles were detected for the 90 accessions, among which 111 were common alleles. The number of alleles per locus ranged from 1 to 9, with an average of 4.0. Polymorphism information content (PIC) values ranged from 0 to 0.856 among all the markers, with an average of 0.547. The PIC value of Qinghai-Tibetan wild barley varied from 0 to 0.813 with an average of 0.543, while in landraces, the markers showed a range of 0 to 0.790 with an average of 0.490. The SSR markers could clearly differentiate the Qinghai-Tibetan wild barley from the landraces. Twenty-four unique alleles were observed in Qinghai-Tibetan wild barley, and the frequency of unique alleles in Qinghai-Tibetan wild barley was about 2.1 times higher than that in the landraces, on average. Five of the 7 chromosomes had more unique alleles in the Qinghai-Tibetan wild barley, but chromosome 2H had more unique alleles in the landraces. The presence of many unique alleles may reflect the adaptation of this barley germplasm to diverse environments and production systems.


Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 595
Author(s):  
Shama Naz ◽  
Qiufang Shen ◽  
Jonas Lwalaba Wa Lwalaba ◽  
Guoping Zhang

Nitrogen (N) availability and form have a dramatic effect on N uptake and assimilation in plants, affecting growth and development. In the previous studies, we found great differences in low-N tolerance between Tibetan wild barley accessions and cultivated barley varieties. We hypothesized that there are different responses to N forms between the two kinds of barleys. Accordingly, this study was carried out to determine the response of four barley genotypes (two wild, XZ16 and XZ179; and two cultivated, ZD9 andHua30) under 4Nforms (NO3−, NH4+, urea and glycine). The results showed significant reduction in growth parameters such as root/shoot length and biomass, as well as photosynthesis parameters and total soluble protein content under glycine treatment relative to other N treatments, for both wild and cultivated barley, however, XZ179 was least affected. Similarly, ammonium adversely affected growth parameters in both wild and cultivated barleys, with XZ179 being severely affected. On the other hand, both wild and cultivated genotypes showed higher biomass, net photosynthetic rate, chlorophyll and protein in NO3− treatment relative to other three N treatments. It may be concluded that barley undisputedly grows well under inorganic nitrogen (NO3−), however in response to the organic N wild barley prefer glycine more than cultivated barely.


1990 ◽  
Vol 68 (12) ◽  
pp. 2564-2570 ◽  
Author(s):  
Suzanne Racette ◽  
Isabelle Louis ◽  
John G. Torrey

The term cluster root is used to refer to a dense cluster of determinate lateral roots (rootlets), in preference to the terms proteoid root and proteoid-like root used by other authors. Cluster roots are often formed by the actinorhizal plant Gymnostoma papuanum. In water culture, cluster root formation by G. papuanum was influenced by aeration, phosphorus level, and nitrogen source. Aeration was a critical factor, with nonaerated rooted cuttings having far fewer cluster roots than aerated ones. Phosphorus deficiency was the single nutrient deficiency that led to increased cluster root formation. Seedlings, grown under conditions of either low (0.8 mg∙L−1) or no phosphorus, responded by devoting a greater portion of root growth to the production of cluster roots, with no overall reduction in root growth for 6 weeks. The response to varying phosphorus level was modified by providing nitrogen in different forms. Supplying nitrogen as ammonium resulted in low levels of cluster root formation. Supplying nitrate to nodulated seedlings led to an increase in cluster root formation in comparison with plants that depended solely upon dinitrogen fixation by Frankia. Greatest cluster root formation occurred on plants grown in aerated water cultures supplied with nitrate and with little or no phosphorus. Key words: Gymnostoma papuanum, cluster roots, proteoid roots, phosphorus deficiency.


1990 ◽  
Vol 17 (4) ◽  
pp. 451 ◽  
Author(s):  
FW Smith ◽  
WA Jackson ◽  
PJV Berg

Partitioning and net transfer of phosphorus between shoots and roots in the tropical forage legume Stylosanthes hamata cv. Verano during the development of phosphorus deficiency has been studied. Plants were stressed by either growing them in dilute flowing culture on continuously maintained external phosphorus concentrations that were inadequate for maximal growth, or by transferring plants of varying phosphorus status to phosphorus-free media. An external phosphorus concentration of 1 �M P was found to be just adequate for maximal growth of S. hamata. Phosphorus stress caused rapid and substantial increases in root weight percentage. It is proposed that this represents an important adaptive mechanism for maximising phosphorus uptake by S. hamata growing in phosphorus-deficient soils. Roots contained the minimum proportion of the plant's phosphorus content when root phosphorus concentrations were 8-10 �mol P g-1 root, and shoot phosphorus concentrations were 16-20 �mol P g-1 shoot. When tissue concentrations were less than these values, plants suffered from phosphorus stress and phosphorus was either preferentially retained by the roots or rapidly transferred from shoots to roots, reducing the growth rates of shoots, but permitting root growth to continue. Upon reducing the external phosphorus supply to plants whose root phosphorus concentrations exceeded 8 to 10 �mol P g-1 root, excess phosphorus was rapidly transferred from the root to the shoot to maintain shoot growth rates. The mobility of phospborus within the plant, and the apparent lack of any delay in transferring phosphorus from shoots to roots as phosphorus stress developed, represent another adaptive feature that is likely to be important to the successful growth of S. hamata in low phosphorus soils. When the phosphorus supply was limited, the plant's resources were directed toward maintaining root growth. Even extremely phosphorus deficient plants, in which shoot growth had ceased, maintained linear rates of root growth. These linear rates were related to the total phosphorus content of the plant. In the latter stages of phosphorus deprivation, linear rates of root growth were maintained by remobilisation of phosphorus from the older parts of the root system to sustain the phosphorus supply to the root meristems.


2020 ◽  
Vol 66 (No. 7) ◽  
pp. 334-344
Author(s):  
Zahra Jabeen ◽  
Nazim Hussain ◽  
Faiza Irshad ◽  
Jianbin Zeng ◽  
Ayesha Tahir ◽  
...  

Saline soil is a critical environmental problem affecting crop yield worldwide. Tibetan wild barley is distinguished for its vast genetic diversity and high degree of tolerance to abiotic stress, including salinity. The present study compared the response of antioxidant defense system in the XZ16 wild and CM72 cultivated barleys to salt stress. Wild barley was relatively more tolerant than cultivated CM72, salt-tolerant cultivar, with less Na<sup>+</sup> uptake and more K<sup>+</sup>, Ca<sup>2+</sup>, and Mg<sup>2+</sup> retention in plant tissues. The results of diaminobenzidine (DAB) and nitroblue tetrazolium (NBT) staining showed that XZ16 had significantly lower H<sub>2</sub>O<sub>2</sub> and O<sub>2</sub><sup>−</sup> concentrations than a salt-sensitive cultivar Gairdner, suggesting that the salt-tolerant genotype suffer from less oxidative damage. Moreover, XZ16 and Gairdner had the highest and lowest anti-oxidative enzyme activities and proline content in plant tissues. In addition, the microscopic examination revealed that DNA damage in cv. Gairdner was closely correlated to oxidative stress, representing that more reactive oxygen species accumulation in plants tissues leads to subsequent DNA damage. The present results show that higher salt tolerance of wild barley XZ16 is attributed to less Na<sup>+</sup> accumulation and stronger anti-oxidative capacity.  


Cells ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1530
Author(s):  
Imrul Mosaddek Ahmed ◽  
Umme Aktari Nadira ◽  
Cheng-Wei Qiu ◽  
Fangbin Cao ◽  
Zhong-Hua Chen ◽  
...  

Drought and salinity are two of the most frequently co-occurring abiotic stresses. Despite recent advances in the elucidation of the effects of these stresses individually during the vegetative stage of plants, significant gaps exist in our understanding of the combined effects of these two frequently co-occurring stresses. Here, Tibetan wild barley XZ5 (drought tolerant), XZ16 (salt tolerant), and cultivated barley cv. CM72 (salt tolerant) were subjected to drought (D), salinity (S), or a combination of both treatments (D+S). Protein synthesis is one of the primary activities of the green part of the plant. Therefore, leaf tissue is an important parameter to evaluate drought and salinity stress conditions. Sixty differentially expressed proteins were identified by mass spectrometry (MALDI-TOF/TOF) and classified into 9 biological processes based on Gene Ontology annotation. Among them, 21 proteins were found to be expressed under drought or salinity alone; however, under D+S, 7 proteins, including S-adenosylmethionine synthetase 3 (SAMS3), were exclusively upregulated in drought-tolerant XZ5 but not in CM72. HvSAMS3 carries both N-terminal and central domains compared with Arabidopsis and activates the expression of several ethylene (ET)-responsive transcription factors. HvSAMS3 is mainly expressed in the roots and stems, and HvSAMS3 is a secretory protein located in the cell membrane and cytoplasm. Barley stripe mosaic virus-based virus-induced gene silencing (BSMV-VIGS) of HvSAMS3 in XZ5 severely compromised its tolerance to D+S and significantly reduced plant growth and K+ uptake. The reduced tolerance to the combined stress was associated with the inhibition of polyamines such as spermidine and spermine, polyamine oxidase, ethylene, biotin, and antioxidant enzyme activities. Furthermore, the exogenous application of ethylene and biotin improved the tolerance to D+S in BSMV-VIGS:HvSAMS3-inoculated plants. Our findings highlight the significance of HvSAMS3 in the tolerance to D+S in XZ5.


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