The Relationship between Salinity and Cadmium Stress in Barley

Distribution of cadmium between roots and shoots of barley was manipulated by the cadmium concentration (0.01 and 0.005 mM Cd²⁺), pH (4.6 and 5.9) as well as treatment duration. The prolongation of treatment increased dry mass and content of cadmium in plants. The cadmium is accumulated mainly in roots. Presence of both, 0.005 mM Cd²⁺ and 100 mM NaCl in medium at pH 5.9 (Cd-NaCl plants) resulted in the most severe growth inhibition of plants, but about one half accumulation of cadmium in roots then in a case of only Cd-treated plants. In the Cd-NaCl plants, the net photosynthetic and transpiration rates were less reduced then in a case of only NaCl-treated plants. The treatments also influenced uptake of Ca, Cd, Cu, K, Mg, Na and Zn predominantly in roots. This revised version was published online in July 2006 with corrections to the Cover Date.     

Evaluation of Barley lncRNAs Expression Analysis in Salinity Stress

Long noncoding RNAs (lncRNAs) act important roles in a wide range of biological processes. The regulatory roles of lncRNAs are still poorly understood. One of the major problems of limiting plant productivity is the salinity in the worldwide that barley (Hordeum vulgare L.) seems to be relatively well adapted to salinity environments. The aim of this study is the investigation of lncRNAs’ expression levels on four barley genotypes (Hasat, Beysehir 99, Konevi 98 and Tarm 92) to 150 mM salt stress application during 3 days germination. Grains were placed randomly in petri dishes containing filter paper soaked in (a) only H₂O (control), (b) 150 mM NaCl for 72 h. RNA extraction were carried out using TriPure® reagent from root and shoot samples obtained after 150 mM salt treatment. Expression levels of CNT0018772 and CNT0031477 were determined by qPCR. Expression analysis demonstrated salinity effected expression levels of CNT0018772 and CNT0031477 on roots and shoots during germination. The expression levels of CNT0018772 for 150 mM salt applied groups were down-regulated raged between (log2–0.52 and–35.65) compared controls on roots and shoot. The expression levels of CNT0031477 in 150 mM salt applied groups were also down-regulated ranged between (log₂–10.40 and 33.59) compared controls on roots and shoot except for Tarm 92 variety. On the contrary, expression levels of CNT0031477 were up-regulated on root and shoot of Tarm 92. Comparison of CNT0018772 and CNT0031477 expression levels on roots, there was no significant difference between barley varieties compared to controls (p > 0.05). However, it was found there was statistically significant difference between 150 mM salt treatment and control groups for CNT0031477 expression levels (p < 0.05). It was determined Konevi 98 shoot control expression level was statistically higher than Tarm 92 shoot control. This is the first report about the lncRNAs expression levels of barley under salinity.     

计算识别microRNA及其靶基因

小RNA的发现为基因调控系统研究提供了新的方向。在多数物种中已经发现了大量的小RNA。这一领域已经成为了近来研究的热点,在研究起始阶段,计算学方法已经成为实验研究中不可或缺的工具,许多发现是由生物学实验与计算学方法共同合作来完成的。在这篇综述中,我们总结了前人关于小RNA及其靶基因识别的理论知识。最后,讨论了关于预测小RNA及其靶基因的计算学方法和相关软件。     

Identification of MicroRNAs and Transcript Targets in Camelina sativa by Deep Sequencing and Computational Methods

Camelina sativa is an annual oilseed crop that is under intensive development for renewable resources of biofuels and industrial oils. MicroRNAs, or miRNAs, are endogenously encoded small RNAs that play key roles in diverse plant biological processes. Here, we conducted deep sequencing on small RNA libraries prepared from camelina leaves, flower buds and two stages of developing seeds corresponding to initial and peak storage products accumulation. Computational analyses identified 207 known miRNAs belonging to 63 families, as well as 5 novel miRNAs. These miRNAs, especially members of the miRNA families, varied greatly in different tissues and developmental stages. The predicted miRNA target genes are involved in a broad range of physiological functions including lipid metabolism. This report is the first step toward elucidating roles of miRNAs in C. sativa and will provide additional tools to improve this oilseed crop for biofuels and biomaterials.     

Identification of microRNAs,phasiRNAs and Their Targets in Pineapple

MicroRNAs (miRNAs) are small non-coding RNAs that regulate their target mRNA levels by directing cleavage or repressing its translation. Besides its outstanding nutritional and medicinal significances, pineapple serves as a model for studying genome evolution in cereal crops as well as obligate crassulacean acid metabolism (CAM) photosynthesis. Thus, studying miRNAs in pineapple is critical for better understanding their roles in this plant species. Here we carried out computational and experimental analysis of miRNAs and phased small interfering RNAs (phasiRNAs) in pineapple by analyzing small RNA profiles from flowers, fruits and leaves. The analyses have identified 131 conserved miRNAs that could be grouped into 37 families and 16 novel miRNAs. Three TAS3 loci and forty five 21 nucleotide (nt) PHAS loci, and seventy three 24 nt PHAS loci were also identified. The putative targets of the identified miRNAs and phasiRNAs were predicted. The presented results provide a comprehensive view of small regulatory RNAs and their targets in pineapple.     

Oxidative Stress Tolerance Mechanism in Rice under Salinity

The research was conducted to investigate comparative oxidative damage including probable protective roles of antioxidant and glyoxalase systems in rice (Oryza sativa L.) seedlings under salinity stress. Seedlings of two rice genotypes: Pokkali (tolerant) and BRRI dhan28 (sensitive) were subjected to 8 dSm⁻¹ salinity stress for seven days in a hydroponic system. We observed significant variation between Pokkali and BRRI dhan28 in phenotypic, biochemical and molecular level under salinity stress. Carotenoid content, ion homeostasis, antioxidant enzymes, ascorbate and glutathione redox system and proline accumulation may help Pokkali to develop defense system during salinity stress. However, the activity antioxidant enzymes particularly superoxide dismutase (SOD), catalase (CAT) and non-chloroplastic peroxidase (POD) were observed significantly higher in Pokkali compared to salt-sensitive BRRI dhan28. Higher glyoxalase (Gly-I) and glyoxalase (Gly-II) activity might have also accompanied Pokkali genotype to reduce potential cytotoxic MG through non-toxic hydroxy acids conversion. However, the efficient antioxidants and glyoxalase system together increased adaptability in Pokkali during salinity stress.     

Genome-Wide Identification of the F-box Gene Family and Expression Analysis under Drought and Salt Stress in Barley

The F-box protein-encoding gene family plays an essential role in plant stress resistance. In present study, 126 non-redundant F-box genes were identified in barley (Hordeum vulgare L., Hv). The corresponding proteins contained 165– 887 amino acid residues and all were amphiphilic, except 5 proteins. Phylogenetic analysis of F-box protein sequences in barley and stress-related F-box protein sequences in wheat and Arabidopsis thaliana (At) was used to classify barley F-box genes are divided into 9 subfamilies (A–I). A structure-based sequence alignment demonstrated that F-box proteins were highly conserved with a total of 10 conserved motifs. In total, 124 F-box genes were unevenly distributed on 7 chromosomes; another 2 genes have not been anchored yet. The gene structure analysis revealed high variability in the number of exons and introns in F-box genes. Comprehensive analysis of expression profiles and phylogenetic tree analysis, a total of 12 F-box genes that may be related to stress tolerance in barley were screened. Of the 12 detected F-box genes, 8 and 10 were upregulated after drought and salt stress treatments, respectively, using quantitative real-time polymerase chain reaction (qRT-PCR). This study is the first systematic analysis conducted on the F-box gene family in barley, which is of great importance for clarifying this family’s bioinformatic characteristics and elucidating its function in barley stress resistance. These results will serve as a theoretical reference for subsequent research on molecular regulation mechanisms, genetic breeding, and improvement.     

A Possible Role for Jasmonic Acid in Adaptation of Barley Seedlings to Salinity Stress

The changes caused by NaCl salinity and jasmonic acid (JA) treatment (8 days) on growth and photosynthesis of barley plants (Hordeum vulgare L., var. Alfa) have been studied. Gas exchange measurements and analysis of enzyme activities were used to study the reactions of photosynthesis to salinity and JA. Both 100 mm NaCl and 25 μm JA treatment led to a noticeable decrease in both the initial slope of the curves representing net photosynthetic rate vs intercellular CO₂ concentration and the maximal rate of photosynthesis. The calculated values of the intercellular CO₂ concentration, CO₂ compensation point, and maximal carboxylating efficiency of ribulose-1,5-bisphosphate carboxylase support the suggestion that biochemical factors are involved in the response of photosynthesis to JA and salinity stress. The activities of phosphoenolpyruvate carboxylase and carbonic anhydrase increased more than twofold. Pretreatment with JA for 4 days before salinization diminished the inhibitory effect of high salt concentration on the growth and photosynthesis. The results are discussed in terms of a possible role of JA in increasing salinity tolerance of the barley plants. Received September 8, 1997; accepted May 19, 1998     

Salicylic Acid-Mediated Regulation of Morpho-Physiological and Yield Attributes of Wheat and Barley Plants in Deferring Salinity Stress

Salinity has been observed to be a global problem that impede the physiological characteristics of plants. Salicylic acid (SA) as a phytohormone play multifaceted role in plants in terms of development as well as stress management. The current study was conducted to evaluate the effect of salinity and salicylic acid on the performance of wheat and barley plants under field experimentation followed by on-farm study to validate the results. This research was firstly conducted in a 4-year research barley field (2012–2013 and 2013–2014) and wheat (2014–2015 and 2015–2016) and subsequently in an on-farm research in four places (2017–2018). Results depicted that salinity decreased plant yield components and altered ion concentrations (Na⁺/K⁺) causing reduced grain and biological yield. However, SA foliar application induced yield components, especially grain number of plants in both years in non-saline and saline conditions. Exogenously SA application not only led to higher grain yield of barley and wheat but also significantly improved their salt tolerance. Our findings revealed that optimum SA concentrations for achieving highest barley yield were 0.85 and 0.78 mM under saline and non-saline conditions, respectively, while on-farm scale studies observed that foliar application of SA increased grain and biological yield of wheat in Ardakan, Ashkzar (saline soil and water) and Mehrabad (non-saline field) regions. There was no significant effect in Tijerd, a completely non-saline field. The grain yields were higher in SA-treated Ardakan, Ashkzar, and Mehrabad plants in field by 19, 16, and 15%, respectively. Based on present detailed studies, it was concluded that SA improved salinity tolerance and increased crop yield. So, optimum concentration (1.0–1.5 mM) with proper time application (double ridges), SA increased wheat and barley yields up to 20%. Therefore, SA priming could be used as a potent strategy to cope up salinity stress from plants.