1 Muhammad Zafar-ul-Hye Volume 4:1, 2020 J Genet Genom.2020.4:1 Journal of Genetics and Genomes Caffeic acid helps to mitigate adverse effects of soil salinity and other abiotic stresses in legumes Muhammad Zafar-ul-Hye*, Muhammad Shakeel Nawaz, Hira Asghar, Muhammad Waqas and Fiza Mahmood *Department of Soil Science, Faculty of Agricultural Sciences and Technology, Bahauddin Zakariya University Multan, Pakistan Abstract Leguminous crops are beneficial components of sustainable crops production. Biotic and abiotic stresses especially salinity is a wide spread environmental problem. It is more profound in the irrigated areas, where the underground water is brackish. Plant vegetative and reproductive growth is adversely affect by salinity and other abiotic stresses like drought and presence of heavy metals etc. Certain organic compounds which are produced at cellular level in plants help in reducing the effect of different stresses through increasing the nutrients uptake efficiency, antioxidants activity and by decreasing the toxicity of ions. Caffeicacid is actively involved in the synthesis of lignin in plants. Increasing the thickness of cell wall and improving plants defense mechanism become active against any stress like ion toxicity and heavy metals contamination. Superoxide radical binds due to use of caffeic acid, thus decreasing the stress of salinity to minimize lipoxygenase function. The ferulic acid is produced through caffeic acid mobilization by o-methyl transferase. Exogenous application of caffeic acid is a good enough option against different stresses like salinity, drought and heavy metals. Key words Nodulation. N-fixation, Antioxidant, Secondary metabolites, Drought, Heavy metals Introduction The leguminous crops play a remarkable role in sustainable crops production. They convert atmosphere nitrogen (N) into the form which is usable by the plants[1]. Soil nutrients status especially N economy improves, if legumes are a part of cropping scenario. Symbiotic relationship of legumes and bacteria helps in this context. The bacterial genera like Rhizobium, Sinorhizobium, Mesorhizobium, and Bradyrhizobium etc., are given special consideration for their role in nodulation and N fixing[2]. Leguminous crops provide the soil with an environmentally safe source of N in comparison with the prevaling use of mineral fertilizers[3]. Certain biotic and abiotic stresses are observed to cause adverse effects on viable symbiotic associations. Stress declines the leguminous crops productivity and their ability of N fixation[4]. Main stressful factors include salinity, drought, heavy metals issues etc.,[5]. Soil Salinity and Leguminous Crops Accumulation of excessive soluble salts in soil is called soil salinity .In Pakistan, salt affected area is 6 mha.It is reported that 70 of tube-well water is brackish in Pakistan. Mostly the underground water contains much more soluble salts. Salt affected area distribution in the Punjab and Sindh provinces is described as 53% and 15.6%, respectively. These area subjected to desertification and abjection. Due to salinity problem the water potential becomes low in soil and plants and consequently the physiological and biochemical processes are affected by various mechanisms. This is how soil salinity exerts negative effects on plants growth and productivity. Legumes show more sensitivity during salinity stress especially at the developmental and seedling stage. Growth process of different legumes like faba bean [6],lentil [7], mung bean [8] and soybean[9] due to salinity has been observed to be affected badly . The reduction in yield of certain legumes at various level of salinity (soil EC) is showed in Table1. Table 1: Reduction in yield of certain legumes at various level of salinity Crop Soil EC Loss in yield (%) Reference Faba bean 6.6 dSm- 1 50 % [11] Mung bean 8.0 dSm- 1 60 % [10] Soybean 7.0 dSm- 1 46 % [12] Review Open Access