The excessive use of chemical fertilizers in conventional agricultural systems decreased the nutrient use efficiency and caused serious environmental problems such as waterway pollution, mineral depletion, soil acidification and other issues. In order to achieve the desirable essential oil productivity and reduction consumption of chemical inputs in peppermint (Mentha x piperita L.), a 2-year field experiment was carried out using a splitplot approach based on a randomized complete block design (RCBD), with 7 treatments and three replications at two harvesting times. The main factor was given by different fertilizer treatments including no fertilizer (control), chemical fertilizer, arbuscular mycorrhiza fungus, 50 % chemical fertilizer + arbuscular mycorrhiza fungus, nano chelated fertilizer, 50 % chemical fertilizer + nano chelated fertilizer, nano chelated fertilizer + arbuscular mycorrhiza fungus, and the sub-factor included two harvesting times (first harvest and second harvest). The results demonstrated that the highest and lowest growth parameters including plant height, number of lateral branches per plant and leaf greenness (SPAD index) were achieved with integrative application of 50 % chemical fertilizer + nano chelated fertilizer (in the first harvest) and control conditions (in the second harvest), respectively. Also, the maximum concentration of N, P, K and Fe was reached in the first harvest with application of 50 % chemical fertilizer + nano chelated fertilizer. Furthermore, the highest peppermint dry matter yield (354.8 g/m2 ), essential oil content (2.7 %) and essential oil yield (6.6 g/m2 ) was achieved at the first harvest with application of 50 % chemical fertilizer + nano chelated fertilizer. GC–MS analysis of peppermint essential oil showed that the major components at first harvest were menthol (31.82–37.87 %), menthone (23.85–30.90 %), 1,8-cineole (6.39–6.82 %), δ-terpineol (3.61–4.11 %) and neo-menthol (2.67–3.33 %), whereas at second harvest menthol (44–47.31 %), p-menth-L-en-9-ol (11.66–14.96 %), menthofuran (3.44–5.14 %), menthone (3.82–10.62 %), 1,8-cineole (5.51–5.99 %) and neo-menthol (5.03–5.90 %). Notably, menthol reached the highest amount with application of 50 % chemical fertilizer + nano chelated fertilizer. Overall, an integrative application of chemical fertilizers with nano fertilizers can be suggested to farmers as an alternative and environmentally friendly strategy to improve the quali-quantitative characteristics of peppermint essential oil.

Introduction

Nowadays, the rapid thrive of global population increased the requirements for food and energy, leading to the enhancement of agricultural productivity in regions with limited cultivation area (Liu and Lal, 2015; Chen and Yada, 2011). In the conventional agricultural systems, the excessive use of chemical inputs allowed to increase the agricultural productivity. Detrimental implications on the environment and human health from intensive agricultural practices and long-term use of chemical fertilizers have been well evidenced (Bansal, 2017). Intensive application of chemical fertilizers has di fferent negative impacts on environment including the aggregation of pesticides and fertilizers, soil erosion, soil and water pollution, genetic erosion, leaching of nutrients and reduction of agrobiodiversity (Daneshmandi and Seyyedi, 2019). The soil health management is crucial for ensuring ecological and agricultural productions and maintaining plant diversity. The negative impacts of chemical fertilizers forced the agrochemical companies to replace them with biofertilizers in sustainable agricultural systems in order to achieve a desirable crop productivity (Sharma et al., 2013). Over 80 % of plant species like those belonging to Fabaceae (Weisany et al., 2016), Asteraceae (Kapoor et al., 2007), Apiaceae (Kapoor et al., 2002) and Lamiaceae (Tarraf et al., 2017) establish mutualistic associations with arbuscular mycorrhiza (AM) fungi.

The plasma membrane (PM) H+ -ATPase is an important ion pump in the plant cell membrane. By extruding protons from the cell and generating a membrane potential, this pump energizes the PM, which is a prerequisite for growth. Modification of the autoinhibitory terminal domains activates PM H+ -ATPase activity, and on this basis it has been hypothesized that these regulatory termini are targets for physiological factors that activate or inhibit proton pumping. In this review, we focus on the posttranslational regulation of the PM H+ -ATPase and place regulation of the pump in an evolutionary and physiological context. The emerging picture is that multiple signals regulating plant growth interfere with the posttranslational regulation of the PM H+ -ATPase.

INTRODUCTION

The plasma membrane (PM) H+ -ATPase is an electrogenic pump that exports cellular protons. In addition to generating a transmembrane chemical gradient of H+ (DpH; acidic on the outside), it also establishes an electrical gradient (the membrane potential; negative on the inside). As almost all other transport proteins in the plant PM are energized by this combined electrochemical gradient of protons, it has been a long-standing hypothesis in plant physiology that the PM H+ – ATPase is a powerhouse for plant growth (reviewed in Palmgren, 2001; Arango et al., 2003; Sondergaard et al., 2004; Duby and Boutry, 2009). However, although the biochemistry of the pump is known in great detail and its structure has been determined (reviewed in Morth et al., 2011), strong evidence for its role in plant growth has remained sparse until recently, when strong links between posttranslational regulation of PM H+ -ATPase and essential physiological functions of plants have emerged. The aim of this review is to provide an overview of this exciting and rapidly developing field.

Plants have always been a key to survival for humans, as they are vital to meet the world’s food needs by contributing about 82% to total global food production harvested from land resources. Historically, over 3000 species of plants have been used to feed humans. Among the plants, wheat is an excellent health building food and an excellent source of minerals, dietary fber, proteins, and B-group vitamins. It is often grown in rain-fed areas (Geravandi et al. 2011) for its starch and protein that makes it the most important cereal crop globally, and, along with rice and maize, forms an integral part of diets of over 4.5 billion people. The success of wheat in temperate world regions is due to its adaptability and high yields together with its unique four dough properties which give it a distinct advantage over the other temperate crops (Shewry 2007). Drought is a polygenic stress (Kilic and Tacettin 2010) that reduces productivity and quality of crops (Waraich et al. 2010, 2011) and also limits the successful realization of land potential throughout the world (Pierre et al. 2012; Liu et al. 2016). The scarcity of water, caused by erratic and poorly distributed rainfall, causes tremendous global losses in agriculture. Russia, for example, has estimated total losses of over US$800 million due to drought and other natural challenges in 2000 alone. Drought afects all plant development stages from germination, vegetative and reproductive growth to grain flling and maturation of the crop (Hossain et al. 2012). Drought reduces nitrogen (N) uptake efciency and utilization by plants. The deprived nutrient uptake is due to impaired membrane permeability and active transport and reduced transpiration rate resulting in repressed root absorbing power. In semi-arid and arid regions of the world, drought is one of the leading causes of limited agriculture production. Many growth variables and functions of plants are afected by water stress (Nezhadahmadi et al. 2013). Under drought conditions, the intake of CO2 is reduced due to stomatal closure, and inside the stomata, a high level of oxygen produces reactive oxygen species, caused by the partial reduction of oxygen, and causes rupturing of membranes which become leaky, thereby afecting respiration, photosynthesis, and the overall development of the plant. Reactive oxygen species also seriously damages the production of cellular components such as carbohydrates, nucleic acids, lipids, and proteins (Waraich et al. 2011; Reddy et al. 2014). Drought is one of the major abiotic stresses that afect at least 60% of wheat production in high-income countries and about 32% of 99 million hectares in low-income least developed countries (Chen et al. 2012). Water defcit might decrease wheat grain yield from 17 to 70% (Nouri-Ganbalani et al. 2009). Daryanto et al. (2016) reported 20.6% yield losses in 40% reduced water. Double ridge to anthesis stage is the most sensitive growth period regarding wheat yield to water defcit because of the negative infuence on number of spikelets and ultimately kernels per spike. Water defcit decreases grain yield by afecting anthesis and grain flling period. It is well documented that plant height, biomass, and yield are more sensitive traits to water defcit in comparison with number of spikes and 1000 grain weight.

Plants close stomata to avoid losing water through transpiration under water limiting conditions (Chaves, 1991), a physiological response that is related to either hydraulic or chemical signals (Davies and Zhang, 1991; Christmann et al., 2007). Plant acclimation to water deficits involves morphological changes that regulate water balance, with plants showing decreases in leaf area and shoot/root ratio (Pimentel, 2004). Cell osmoregulation by solutes such as sugars, glycine-betaine, and proline is another response to water deficits, allowing the maintenance of water content and protecting cellular structures (Verlues et al., 2006). Rapid stomatal response to changes in water availability is an important feature in sugarcane (Saccharum spp.), preventing excessive loss of leaf turgor and further decreases in leaf water content (Ribeiro et al., 2013). However, it is well-known that stomatal closure causes low CO2 availability for photosynthetic enzymes (Du et al., 1996; Chaves et al., 2009; Machado et al., 2013) and then an imbalance between photochemical and biochemical reactions in the leaves. Therefore, production of reactive oxygen species (ROS) is enhanced under drought conditions, and plants should be able to control such deleterious molecules through their antioxidant system. This protective system consists of several enzymatic and non-enzymatic compounds, which prevent oxidative damage by scavenging ROS inside cells (Mittler, 2002). For instance, increases in superoxide dismutase and ascorbate peroxidase activities were associated with rapid recovery of leaf gas exchange in sugarcane plants after rehydration (Sales et al., 2013). These reported plant responses to a single drought event are quite common; however, plants are exposed to recurrent cycles of drought and rehydration in nature, and the consequences of such repetitive drought events are less understood (Walter et al., 2011). Plants can acclimate to varying water conditions through morphological and physiological changes, which favor the maintenance of plant growth or survival under stressful conditions (Chaves et al., 2002). Some changes during an acclimation period can allow faster responses and enhanced plant performances during the next stressful event. In fact, an experimental design with repeated cycles of droughts is a more realistic approach when considering plants in their natural environment, with improved plant performances under limiting conditions being found in several species when there was previous exposure to stressful conditions. While Trifolium alexandrinum was able to maintain high leaf water potential and relative water content after a second drought event (Iannucci et al., 2000), Quercus ilex exhibited reductions in leaf water potential and transpiration accompanied by osmotic adjustment after hardening (Villar-Salvador et al., 2004). Seedlings of Moringa oleifera that had previously been subjected to osmotic stress experienced increased drought tolerance, with plants showing higher water-use efficiency, higher photosynthesis and increases in activity of antioxidant enzymes under water deficit conditions (Rivas et al., 2013). However, most of these studies compared plants of differing ages under varying stress intensities and environmental conditions, which makes the study of stress memory difficult.

Reduction of growth rates below their optimum levels occurs under the environmental conditions referred to as abiotic stress (Cramer et al. 2011). Plants respond dynamically and reversibly to abiotic stress (Skirycz and Inzé 2010), because they must adapt to new conditions, and this response affects their growth and development (Santner and Estelle 2009). Abiotic stresses such as high salinity and drought always cause reductions in plant growth (Huang et al. 2012). Drought is an abiotic environmental factor and major stressor, which can decrease the plant’s development rate and its productivity (Agarwal et al. 2013). The nucleocytoplasmic receptors pyrabactin resistance (PYR), pyrabactin resistance-like (PYL), and regulatory component of abscisic acid (ABA) receptor (RCAR) bind to ABA phytohormone and inhibits type 2C protein phosphatases (PP2Cs) such as ABI1 and ABI2 (Park et al. 2009). Inactivation of PP2Cs leads to accumulation of active SNF1-related protein kinases/SnRK2s (Park et al. 2009; Umezawa et al. 2009). SnRK2s regulate ABA responsive transcription factors such as ABA-responsive element binding proteins (AREBs), leading to activation of ABA-responsive genes and ABA-related processes (Umezawa et al. 2009). Drought sensitive 1 (DRS1) is an ABA-dependent responsive gene required for ABA dependent signaling (Lee et al. 2010). ABA allows adaptation of plant cells to drought stress as a phytohormone and produced under drought stress and high salinity conditions.  ABA promotes tolerance to drought and salt stresses by controlling stomatal closure during daytime to avoid loss of water as well as activation of stress-related genes in plant cells (Nakashima et al. 2012). These stress-related genes can protect plant cells through the production of functional regulatory proteins and enzymes for cell signal transduction (Nakashima et al. 2012). The DRS1 gene is upregulated under water deficiency, and promotes tolerance to drought stress mediated by ABA. This gene encodes a WD-40 repeat 70 family protein involved in DDB1-CUL4-mediated protein degradation during the drought response, which was confirmed genetically using a genomic functional network modeling system. These findings suggest a significant association between DRS1 and ABA-mediated 73 responses to water deficiency in plants (Lee et al. 2010, 2011; Winkler et al. 2015).

مقاله سال 2016

مقدمه
اگرچه گیاهان اکسیژن را از طریق فتوسنتز تولید می کنند ، اما کمبود یک سیستم کارآمد برای انتقال اکسیژن به ارگان های غیر فتوسنتزی نشان می دهد که این ارگان ها ممکن است در صورت محدود شدن اکسیژن از خارج ، از اکسیژن محدود شوند. علاوه بر این ، غوطه ور شدن کامل گیاه به واسطه ی سیل ممکن است منجر به دسترسی پایین به اکسیژن در اندام های بالاتر از زمین شود ، به خصوص زمانی که آلودگی آب فتوسنتز را محدود می کند. زمانی که اکسیژن برای تنفس محدود شود ، گیاهان هیپوکسی را تجربه می کنند ، در حالی که فقدان کامل اکسیژن (آنوکسی) برای بقای گیاه بیش تر مضر است. هم هیپوکسی و هم آنوکسی (کمبود اکسیژن) موجب برنامه نویسی مجدد ساختار ژن با القای متابولیسم خمیری می شوند و گیاه را قادر به استفاده از گلیکولیز برای تولید ATP می سازند. تغییرات آب و هوا باعث دسترسی بیش از اندازه به آب می شوند و در برخی نواحی منجر به خشکسالی می شوند ، در حالی که جاری شدن سیل به علت بارندگی شدید سایر مناطق جغرافیایی را تحت تاثیر قرار می دهد. به غیر از این در برخی از موارد انواع جدید محصولات قادر به مقاومت در برابر تنش های غیر زنده می باشند ، و حاصلخیزی به شدت تحت تاثیر قرار خواهد گرفت. تا یک دهه پیش اطلاعات کمی در رابطه با ژن هایی که تحمل در برابر غوطه ور شدن را افزایش می دادند وجود داشت ، و در طول سال های اخیر مکانیسم های ملکولی مربوط به سنجش اکسیژن و سیگنال دهی در گیاهان توسعه یافتند. در این بررسی ، یافته های اخیر در زمینه ی گیاهان غیرهوازی از اکوفیزیولوژی گیاهان که در تالاب ها رشد می کنند ، مورد توجه قرار دارند.

مقاله سال 2016