%0 Journal Article %T Enhanced Photosynthesis and Carbon Metabolism Favor Arsenic Tolerance in Artemisia annua, a Medicinal Plant as Revealed by Homology-Based Proteomics %A Rashmi Rai %A Sarita Pandey %A Alok Kumar Shrivastava %A Shashi Pandey Rai %J International Journal of Proteomics %D 2014 %I Hindawi Publishing Corporation %R 10.1155/2014/163962 %X This paper provides the first proteomic evidence of arsenic (As) tolerance and interactive regulatory network between primary and secondary metabolism in the medicinal plant, Artemisia annua. While chlorophyll fluorescence and photosynthetic rate depicted mild inhibition, there was a significant enhancement in PSI activity, whole chain, ATP, and NADPH contents in 100£¿¦ÌM As treatments compared to the control plants. However, a decrease in the above variables was recorded under 150£¿¦ÌM treatments. Proteomic decoding of the survival strategy of A. annua under As stress using 2-DE followed by MALDI-MS/MS revealed a total of 46 differentially expressed protein spots. In contrast to other plants where As inhibits photosynthesis, A. annua showed appreciable photosynthetic CO2 assimilation and allocation of carbon resources at 100£¿¦ÌM As concentration. While an increased accumulation of ATP synthase, ferredoxin-NADP(H) oxidoreductase, and FeS-rieske proteins supported the operation of cyclic electron transport, mdr ABC transporter protein and pcs gene might be involved in As detoxification. The most interesting observation was an increased accumulation of LEAFY like novel protein conceivably responsible for an early onset of flowering in A. annua under As stress. This study not only affirmed the role of energy metabolism proteins but also identified potential candidates responsible for As tolerance in plants. 1. Introduction In recent years, metal/metalloid contamination has resulted in degradation of large areas of cultivable lands, posing a serious threat to sustainable agriculture and food security in developing countries like India [1]. The frequent use of As-laden ground water for irrigation elevates As levels in the soils and makes land unproductive and toxic, thereby resulting in severe reduction of growth and yield of food crops [2, 3]. This calls for judicious management of contaminated lands to put them back in cultivation. Although a number of As-tolerant noncommercial plants, including some species of the genera Pteris, Agrostis, Lepidium, Lemna, and Jasione, are known to accumulate high levels of As and have been successfully exploited for As phytoremediation [4, 5], none of these have any commercial use. Hence, it is highly desirable to identify nonedible plant species which may not only be cultivated for phytoremediation of As contaminated soils but also put back into commercial use. Artemisia annua (Asteraceae) is an important dicotyledonous medicinal plant native from China and widely distributed in temperate and subtropical zones of the world, %U http://www.hindawi.com/journals/ijpro/2014/163962/