Agricultural production and quality are adversely affected by various abiotic stresses worldwide and this will be exacerbated by the deterioration of global climate. To feed a growing world ...population, it is very urgent to breed stress-tolerant crops with higher yields and improved qualities against multiple environmental stresses. Since conventional breeding approaches had marginal success due to the complexity of stress tolerance traits, the transgenic approach is now being popularly used to breed stress-tolerant crops. So identifying and characterizing the critical genes involved in plant stress responses is an essential prerequisite for engineering stress-tolerant crops. Far beyond the manipulation of single functional gene, engineering certain regulatory genes has emerged as an effective strategy now for controlling the expression of many stress-responsive genes. Transcription factors (TFs) are good candidates for genetic engineering to breed stress-tolerant crop because of their role as master regulators of many stress-responsive genes. Many TFs belonging to families AP2/EREBP, MYB, WRKY, NAC, bZIP have been found to be involved in various abiotic stresses and some TF genes have also been engineered to improve stress tolerance in model and crop plants. In this review, we take five large families of TFs as examples and review the recent progress of TFs involved in plant abiotic stress responses and their potential utilization to improve multiple stress tolerance of crops in the field conditions.
Genetic engineering has a wide range of cultural, economic, and ethical implications, yet it has become almost an article of faith that regulatory decisions about biotechnology be based only on ...evidence of specific quantifiable risks; to consider anything else is said to "politicize" regulation. In this study of social protest against genetically engineered food, Abby Kinchy turns the conventional argument on its head. Rather than consider politicization of the regulatory system, she takes a close look at the scientization of public debate about the "contamination" of crops resulting from pollen drift and seed mixing. Advocates of alternative agriculture confront the scientization of this debate by calling on international experts, carrying out their own research, questioning regulatory science in court, building alternative markets, and demanding that their governments consider the social and economic impacts of the new technologies. Kinchy focuses on social conflicts over canola in Canada and maize in Mexico, drawing out their linkages to the global food system and international environmental governance. The book ultimately demonstrates the shortcomings of dominant models of scientific risk governance, which marginalize alternative visions of rural livelihoods and sustainable food production.The hardcover edition does not include a dust jacket.
Abiotic stresses have a detrimental impact on plant growth and productivity and are a major threat to sustainable crop production in rapidly changing environments. Proline, an important amino acid, ...plays an important role in maintaining the metabolism and growth of plants under abiotic stress conditions. Many insights indicate a positive relationship between proline accumulation and tolerance of plants to various abiotic stresses. Because of its metal chelator properties, it acts as a molecular chaperone, an antioxidative defence molecule that scavenges reactive oxygen species (ROS), as well as having signalling behaviour to activate specific gene functions that are crucial for plant recovery from stresses. It also acts as an osmoprotectant, a potential source to acquire nitrogen as well as carbon, and plays a significant role in the flowering and development of plants. Overproduction of proline in plant cells contributes to maintaining cellular homeostasis, water uptake, osmotic adjustment and redox balance to restore the cell structures and mitigate oxidative damage. Many reports reveal that transgenic plants, particularly those overexpressing genes tailored for proline accumulation, exhibit better adaptation to abiotic stresses. Therefore, this review aims to provide a comprehensive update on proline biosynthesis and accumulation in plants and its putative regulatory roles in mediating plant defence against abiotic stresses. Additionally, the current and future directions in research concerning manipulation of proline to induce gene functions that appear promising in genetics and genomics approaches to improve plant adaptive responses under changing climate conditions are also highlighted.
Proline has multifaceted functions to combat abiotic stress in plants.
Summary
Genotype specificity is a big problem lagging the development of efficient hexaploid wheat transformation system. Increasingly, the biosecurity of genetically modified organisms is garnering ...public attention, so the generation of marker‐free transgenic plants is very important to the eventual potential commercial release of transgenic wheat. In this study, 15 commercial Chinese hexaploid wheat varieties were successfully transformed via an Agrobacterium‐mediated method, with efficiency of up to 37.7%, as confirmed by the use of Quickstix strips, histochemical staining, PCR analysis and Southern blotting. Of particular interest, marker‐free transgenic wheat plants from various commercial Chinese varieties and their F1 hybrids were successfully obtained for the first time, with a frequency of 4.3%, using a plasmid harbouring two independent T‐DNA regions. The average co‐integration frequency of the gus and the bar genes located on the two independent T‐DNA regions was 49.0% in T0 plants. We further found that the efficiency of generating marker‐free plants was related to the number of bar gene copies integrated in the genome. Marker‐free transgenic wheat plants were identified in the progeny of three transgenic lines that had only one or two bar gene copies. Moreover, silencing of the bar gene was detected in 30.7% of T1 positive plants, but the gus gene was never found to be silenced in T1 plants. Bisulphite genomic sequencing suggested that DNA methylation in the 35S promoter of the bar gene regulatory region might be the main reason for bar gene silencing in the transgenic plants.
Through the development of plant culture and imaging system, a low-cost plant living fluorescence imaging system was developed. The system adopts a double-layer box structure design, which is divided ...into two parts: the constant culture system and the fluorescence recording system. It can provide the necessary life support function for plant growth, and can also obtain the key images in the process of plant growth in real time, including the time-space mode of monitoring the fluorescence signal in the development of the transgenic plant. The EGFP transgenic tobacco and Arabidopsis were successfully cultured and observed in real time using this system. The low cost greatly expanded the application of the system in experimental teaching, and also laid a foundation for the further study of the observation and detection of follow-up life activities.
Plant-mediated RNA interference (RNAi) shows great potential in crop protection. It relies on plants stably expressing double-stranded RNAs (dsRNAs) that target essential genes in pest insects. ...Practical application of this strategy is challenging because producing sufficient amounts of stable dsRNA in plants has proven to be difficult to achieve with conventional transgenesis. In addition, many insects do not respond to exogenously applied dsRNAs, either degrading them or failing to import them into the cytoplasm. We summarize recent progress in RNAi-mediated insect pest control and discuss factors determining its efficacy. Expressing dsRNA in chloroplasts overcomes many of the difficulties previously encountered. We also highlight remaining challenges and discuss the environmental and biosafety issues involved in the use of this technology in agriculture.
Plant-mediated RNAi that targets essential genes in insects and other pests is becoming a promising approach in crop protection.
Expression of dsRNA targeting insect genes can potentially provide crop protection without chemical pesticides and offers the additional advantages that no foreign protein is made and the number of target genes is nearly unlimited.
The length and amount of the dsRNA as well as its stability in planta and in the gut of the target insect are crucial factors determining the success of plant-mediated RNAi strategies.
High-level expression of long dsRNAs from the genome of the chloroplast represents a particularly promising strategy for efficient RNAi-mediated crop protection.
Plant salt-tolerance mechanism: A review Liang, Wenji; Ma, Xiaoli; Wan, Peng ...
Biochemical and biophysical research communications,
01/2018, Volume:
495, Issue:
1
Journal Article
Peer reviewed
Almost all crops that are important to humans are sensitive to high salt concentration in the soil. The presence of salt in soil is one of the most significant abiotic stresses in farming. Therefore, ...improving plant salt tolerance and increasing the yield and quality of crops in salty land is vital. Transgenic technology is a fast and effective method to obtain salt-tolerant varieties. At present, many scholars have studied salt damage to plant and plant salt-tolerance mechanism. These scholars have cloned a number of salt-related genes and achieved high salt tolerance for transgenic plants, thereby showing attractive prospects.
In this paper, the salt-tolerance mechanism of plants is described from four aspects: plant osmotic stress, ion toxicity, oxidative stress, and salt tolerance genes. This review may help in studies to reveal the mechanism of plant salt tolerance, screen high efficiency and quality salt tolerance crops.
•The crops production were significantly inhibited by salt.•It is particularly important to study the function of salt tolerant genes.•We described plant salt tolerance mechanism from four aspects.•They were osmotic stress, ion toxicity, oxidative stress and salt tolerance genes.
Abiotic stresses, such as heat, drought, salinity, low temperature, and heavy metals, inhibit plant growth and reduce crop productivity. Abiotic stresses are becoming increasingly extreme worldwide ...due to the ongoing deterioration of the global climate and the increase in agrochemical utilization and industrialization. Plants grown in fields are affected by one or more abiotic stresses. The consequent stress response of plants induces reactive oxygen species (ROS), which are then used as signaling molecules to activate stress‐tolerance mechanism. However, under extreme stress conditions, ROS are overproduced and cause oxidative damage to plants. In such conditions, plants produce anthocyanins after ROS signaling via the transcription of anthocyanin biosynthesis genes. These anthocyanins are then utilized in antioxidant activities by scavenging excess ROS for their sustainability. In this review, we discuss the physiological, biochemical, and molecular mechanisms underlying abiotic stress‐induced anthocyanins in plants and their role in abiotic stress tolerance. In addition, we highlight the current progress in the development of anthocyanin‐enriched transgenic plants and their ability to increase abiotic stress tolerance. Overall, this review provides valuable information that increases our understanding of the mechanisms by which anthocyanins respond to abiotic stress and protect plants against it. This review also provides practical guidance for plant biologists who are engineering stress‐tolerant crops using anthocyanin biosynthesis or regulatory genes.
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