IndexIntroductionThe water problem in EgyptEffects on plants due to the water problem in EgyptThe biochemical and molecular response to droughtSummaryReferencesIntroductionStress is an external factor that influences the growth of plants plant. There are types of stress. Biotic stress, abiotic stress. Bacteria, fungi, insects, weeds, nematodes and biotic stress arachids. Salinity, drought, cold, high temperatures from abiotic stress. We will talk about the drought in Egypt as an example of stress. So the water problem in Egypt arises from the reasons for the drought in Egypt. Furthermore, the effect of stress on plant productivity as well as plant development. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay Assuming continued population growth and taking into account desert land reclamation projects and the fact that more than 50% of grains consumed are already imported, Egypt cannot meet its food demand by relying on Nile water for irrigation. In other words, Egypt is already using most of the Nile's flow and plans to use even more. According to the Ministry of Water Resources and Irrigation, the national water budget is in deficit. So Egypt faces a big drought problem affecting plants. So there are responses from plants to deal with drought. The plant has biochemical, molecular, physiological and morphological responses. Morphological responses such as reduced plant size and leaf area. Physiological response such as closure of stomata, decrease in photosynthesis activity. Biochemical responses such as a reduction in photochemical efficiency, reduction of antioxidant enzymes (superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR) which are a very important enzyme. responses , some genes have effects on drought stress, so they produce different types of proteins related to LEB proteins, the expression of ABA genes, the production of RAB proteins exerts negative effects on many crops during germination to make certain chemicals or proteins have a defense role against drought stress or even some proteins. From this defense increases the antioxidant, whose role is too protective catalyzed by enzymes to clean up the system in the toxicity plants such as the carotenoid antioxidant glutathione ascorbate known as SOD, gene transpiration was known to decrease significantly under drought stress, so heat could be slowly lost from leaves and leaf temperature could increase; Plant growth is negatively affected by molecular alterations under stress. Drought stress induces the transcription of number of genes, however the transcription of genes in response to both stresses is quite different. Transcription of dreb1 also called CBFSOR, c-box binding factors and DREB2 families were affected in defense against chilling and drought stresses. In this way the plants defend themselves from the stress caused by drought. The water problem in Egypt Water scarcity is problematic in Egypt. the rate of water presence per capita is already the lowest in the world. this is suggested for further decreases. An important challenge is to quickly bridge the large gap between limited water availability and growing demand from various economic sectors. The Nile is the main source of water in Egypt with a share of more than 95%. the lake nasser storage basin provides 56 billion m3 hereinafter referred to inbillion cubic meters per year. the issue of Egypt's share of the Nile waters is the subject of difficult negotiations. in April 2011, Ethiopia started construction of the large GERD dam to shape water quality. With a water storage capacity of 63 billion cubic meters and a power generation capacity of 6,000 MW, GERD is expected to be the largest hydropower plant and one of the continent's water reservoirs. Egyptian experts give indications of a water reduction of 20-34% when the filling period exceeds the dry period. this will average 11-19 billion cubic meters during the dam filling period. Effects of plants due to water problem in EgyptEgyptian scientists warn of increasing water poverty in Egypt due to the Ethiopian Renaissance Dam that is about to become operational. Egypt is reducing the cultivation of water-consuming crops such as rice. By rejecting the cultivation of some crops we are risking the great loss of large agricultural lands, this will have a very negative impact on soil salinity in some agricultural lands, which will be disastrous for the agricultural sector. Analysis of variance showed significant and highly significant effects for irrigation. treatments on grain yield in the 1st and 2nd season respectively. As shown, wheat yield decreased significantly from 5.88 to 3.73 tonnes/ha, on average in both seasons, with a decrease in the number of irrigations from seven to two irrigations/season. These results could be attributed mainly to the decrease in ears per unit area and grains per ear, also attributed to a reduction in the number of effective growers. Our results are in agreement with soil properties. The biochemical and molecular response to drought Rice is a very important food crop and requires a large amount of water to grow. Rice plays a vital role as a staple food that feeds more than three billion people. Rice plays an important role in Egypt. Identifying rice genotypes and breeding lines with high levels of drought tolerance for use as inbreeding and gene discovery are challenges for rice research. Drought is the most important stress affecting plant growth. And it is also a challenge for agricultural researchers and plant breeders. Water stress causes many threats in rice and affects the morphological, physiological, biochemical and molecular characteristics of rice crops along with its productivity. Biochemical traits affecting drought stress in rice. Are we going to talk about the increase and decrease of some chemicals and some enzymes? Enzyme with antioxidant characteristics observed that is in high concentration in drought stress to overcome the toxicity caused by this stress. A decrease caused by drought-related water content in the leaves that changes in the plant that observed chlorophyll synthesis but not greatly reduced due to drought stress. Membrane stability index representing drought tolerance genotype. The percentage of proline increases in the leaf more than an amino acid due to the decrease in water which acts as an osmolyte in case of lack of water also chelator of metals an antioxidant defense molecule. Proline can be used as a screening marker to ensure that rice is tolerant. Peroxidase activity also increases in the absence of water. Catalase activity has a notable increase during water harvesting. So plants with a higher level of antioxidant system and substrate have tolerance to drought stress. Plants sometimes have to be exposed to stressfrom drought due to lack of water and plants must have a response to this stress to keep the plants alive or tolerant of this situation. From these answers, the molecular response in the next lines will talk about genes expressed in the presence of lack of water stress. SNAC1, the PoPW gene enhancing overexpression of this gene, enhanced the relative transcription level of drought-responsible genes such as NtAPX, NtCAT1, NtGST, and Ntcuzn-SOD. The LEA gene also has a role in the plant that increases tolerance to water deficiency stress through a decrease in photosynthetic activity and increases the activation of the antioxidant system. Environmental diversity and drought pose a serious threat to larger crops. Drought stress is one of the consequences of environmental diversity that damages crop growth and yield. Extremely important to improve crops essential to address the challenges of drought stress that defines crop fertility and production. Wheat is one of several crops that are popular and universally used for its economic and social benefits. Many nations depend on wheat, this crop for food and feed, and this crop is not protected from drought stress. Improving drought stress tolerance is an extremely challenging task for wheat. The wheat genotype has a high degree of drought tolerance and choice with their descendants. Furthermore, it is very useful to distinguish genes that contribute to drought tolerance. Drought stress can be simply described as a lack of water that induces tense, biochemical and molecular changes. All these differences reduce plant growth and harvested product. Wheat is an important cereal crop and much of the human population in many parts of the world uses it as a source of food and animals? Wheat is a very important crop. From the biochemical response to drought stress, some chemicals or enzymes included and we will talk about them in the next lines. Reactive oxygen species (ROS) can be singlet oxygen, superoxide radicals (O2), (H2O2), and (OH) have caused oxidative damage to plants. The presence of ROS causes the alteration of cellular water. ROS production is linear with the severity of water stress which triggered membrane peroxidation as a defense against stress. Generation of antioxidant enzymes as defense against drought stress such as catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX), hydroascorbate reductase (DHAR) and glutathione reductase and glutathione peroxidase ( GPX) in response to water stress is a well-known adaptive mechanism in wheat. Plant acclimation to water deficit classified into three classes: drought escape, dehydration avoidance, dehydration tolerance or its combination. Osmolyte accumulation is one of the drought tolerance mechanisms that allows cells to control their dehydration and membrane structural integrity during drought stress to give tolerance to drought and cellular dehydration. Osmotic organization in plants exposed to drought may correspond to the storage of low molecular weight organic solutes. The wheat plant reserves various inorganic and organic solutes in its cytosol to decrease its osmotic potential for maintaining cellular turgor. From these hormones the generation of abscisic acid (ABA) can influence drought acclimation by both avoiding dehydration and tolerating dehydration as protection from drought stress. . Abscisic acid (ABA) is the most important hormone required to control tolerance to abiotic stresses such as drought, salinity, cold, heat and injury.(ABA) has long been recognized as an important chemical stress signal from roots to shoots that induces leaf growth inhibition and short-term responses such as stomatal closure. ABA is included in the control of systemic responses to abiotic stress before detectable changes in leaf water occur. Water content, relative water content, succulence index, water loss rate, increased leaf water recognition and further transpiration rate are some essential characteristics that influence plant water ratios. Relative water content (RWC) is a type of plant water state, which corresponds to the metabolic blueprint in tissues. It is used as a common essential index for dehydration tolerance. A reduction in RWC in response to drought stress has been observed in a wide variety of plants. Water deficiency is a significant environmental stress that facilitates the production of reactive oxygen species (ROS). Access in ROS generation causes molecular responses, which are critical agents in managing the level of tolerance of plants to stresses, including drought. This research is aimed at defining the expression levels of the genes encoding MAPKs (MAPK3 and MAPK6), antioxidant enzymes (CAT, APX and GPX) and enzymes required in proline biosynthesis (P5CS and P5CR) in Triticum aestivum L seedlings. in response to short-term drought circumstances. A panel of wheat intervarietal replacement lines (ISCSLs) obtained by replacing single chromosomes from a drought-sensitive cultivar into the genetic background of a drought-resistant cultivar was applied. This source element provided the chromosomal localization of the genetic elements included in the response to the analyzed stress agent (drought). The findings showed that the original plant response to drought stress occurred particularly in changes in the expression of MAPK6 and CAT and both P5CS and P5CR genes. Our results explained that chromosome replacement had the greatest influence on the expression level of all tested genes, which means that they include genetic factors that have an important purpose in managing water deficiency tolerance in the wheat genome.MAPK (MAPK3 and MAPK6) genes: Most ISCSLs noted an accession in the transcription level of MAPK6 after 6 hours. However, complex expression patterns have been recognized across antistress drugs for several lineages. Rapid onset of MAPK6 already occurred after 1 h in the drought-tolerant cultivar. A viable increase in MAPK6 transcript levels was recognized for those lines after 3 hours of exposure to 10% PEG. However, the decrease in MAPK3 expression after 1 hour of PEG medicine. Downregulation of MAPK3 was observed at the following time points (after 3 and 6 hours). In some cultivars, a significant induction of MAPK3 was recognized in the first hours of stress for drought-resistant subjects, followed by a rapid reduction in transcription levels. For the remaining forms, no induction of MAPK3 was noted in the first hours of plant exposure to drought, and then a significant reduction occurred. (P5CS and P5CR): overexpression of the P5CS gene leads to an extension of the amount of proline and improved stress tolerance. TaMAPK3: TaMAPK3 transcript levels were significantly reduced after 6 hours of exposure in the majority of lines tested. The P5CS and P5CR Genes: The research results showed an important accession in the expression of both P5CS and P5CR genes. However, elevated levels of P5CS gene transcription were observed directly after 1,