Morphological Parameters & Identification of Nhx1 of Petroselinum Crispum

Salinity is one of the major issue which ultimately leads towards loss of yield among important crops. For all significant crops, average harvests area fraction – anywhere amongst 20% and 50% of record yields; these losses arebecause of drought and high soil salinity. A wide range of strategies is needed to manage with such effects. There is a requirement to developbiological methods for salinity stress management that are simple and low cost.There is a range of plants recognized as glycophytes, which are salt sensitive and Generally, our major crops are glycophytic in nature. Parsley (Petroselinum crispum) is a biennial herb belongs to Apiaceae family and has higher medicinal values and as a seasoning as well as garnish agent in food industry. It can grow dynamically in the harsh environment with the scarcity of nutrients. Although P. crispum has been explored widely for its medicinal values.

Thus, in current study effect of NaCl (Control, 25-, 50-, and 100-µM) concentrations on the root/shoot length, fresh/dry weights, identification of the NHX1 has been purposed to investigate, while using hydroponic culture.Introduction21st century is being characterizedby the international shortage ofwater, polluted environment along with thesalinization of soil and water. There are two intimidations for an agronomic sustainability i.e., increase in human population and the decrease in accessible land (Shahbaz et al.,2013) . One of main reason for the natural soil salinity is the fluctuation of water table. As the water table fluctuates, the crops are unable to be use significant volume of water. As a result, soil allows more rainfall penetration and causes water table to rise (Jardine et al. 2007) ultimately increasing the salinity problem.

Natural salts are mobilized and elevate to the surface causing salt deposit to increase in comparison to the natural level (Mills et al. 2016). In most of the areas, the soil salinity problem is due to the rapid expansion of irrigation (Shrivastava et al., 2015). Anthropogenic is the other major cause of soil salinity. Use of inappropriate cultivation techniques, extensive use of fuels, increasing number industries and use of urban water have led to the deposition of large quantities of salt in the upper soil (Sytar et al., 2018).

Soil salinity, mainly NaCl confines the growth and production of numerous crop plants. Salinity not only reduced the crop yield per hectare but also declines the arable land. Such losses are compounded by the extra challenges that agriculture requires to offer enough diet for world population (with superior life style)that is increasing at alarming rate(Schroeder et al. 2013).Higher concentration of NaCl in plants primarily induced osmotic and/or ionic stresses which finally lead to secondary stresses i.e., oxidative and related stresses (Flowers et al., 2008).

To survive with an unfavorable concentration of Na+, the plant uses diverse approaches to sustain a low level of the cytosolic Na+. These approaches comprise; 1. Reduced Na+ entrance in to plant cells 2. Na+ compartmentalization into vacuole 3. Efflux of the Na+ from root tip (Aharon et al.,2000). There are many genes (SOS1, NHX1, HKT1/2) which are involved in these metabolic activities and ionic homeostasis to enable the plant to withstand the higher Na+ concentrations in its surrounding environment. Numerous antiporter genesNa+/H+ like NHX’s has been reported in many plants(Yokoi et al. 2002) and phylogenetic/sequence analysis of existing plant genomes predicts that these are abundant to all eukaryotes. NHX has six isoforms in Arabidopsis (NHX1-6). AtNHX1 and AtNHX2 are expressed strongly in whole plant body other than the root tip, however the transcripts of AtNHX3 and AtNHX4 are almost present only in root and flowers tissue (Silva et al., 2009).

All above mentioned NHX’s are localized to the vacuolar membrane, while AtNHX5 and AtNHX-6 are present on the endosomal area (Bassil et al. 2011) . There are twelve transmembrane domains for the NHX1 protein(Sato et al., 2005) which have C-terminal in cytosol (hydrophilic) and N-terminal in in lumina (hydrophobic). Predicted active sites for the NHX are lies in transmembrane domains beween five and six (Silva et al., 2009).Under salt stress, the levels of transcript for these genes was found to beupregulated(Blumwald et al.,2000; Shi et al. 2003). When NHX1 overexpressed in A. thaliana from other plant species like cotton (Gossypium hirsutum), wheat (Triticum aestivum), Suaeda salsa (a halophytes) and from yeast, it not only increased the salt tolerance of the transgenic but also scavenge the ROS (Reactive Oxygen Species) in a better way along with much higher photosynthetic process under salinity stress(Liu et al. 2010). Recently, it has been documented that NHX1-type protein is crucial for cellular pH homeostasis as well as for the K+ compartmentalization (Barragan et al. 2012).

Some other functions like vesicular trafficking, protein processing has also been associated with the endosomal NHX antiporters(Bassil et al. 2011). Vacuolar K+ as well as K+ transport from root to shoot through the overexpression of NHX1 in tomato, and it is beneficial because improved intracellular K+/Na+ ratios decrease Na+ pressure. accretion (Bassil et al. 2011). Furthermore, tomato LeNHX3 gene maps to QTL linked with leaf Na+ accretion (Villalta et al. 2008). Statement of the ProblemPurpose of studyP. crispum, having many medicinal usages, tremendous ability to withstand extreme environmental conditions. We will explore its ability to to tolerate higher concentrations of salt as well as identify a salt tolerant candidate gene i.e., NHX1 from P. crispum.