Glycinebetaine (GB) is present abundantly in chloroplast whe...

created [InstanceEdit:8858207] Amarasinghe, Vindhya, 2016-02-17
dbId 8858226
displayName Glycinebetaine (GB) is present abundantly in chloroplast whe...
modified [InstanceEdit:8858246] Amarasinghe, Vindhya, 2016-02-17
schemaClass Summation
text Glycinebetaine (GB) is present abundantly in chloroplast where it plays a vital role in adjustment and protection of thylakoid membrane, thereby maintaining photosynthetic efficiency. In higher plants, GB is synthesized in chloroplast from serine via ethanolamine, choline, and betaine aldehyde. Choline is converted to betaine aldehyde, by choline monooxygenase (CMO), which is then converted to GB by betaine aldehyde dehydrogenase (BADH) (Ashraf and Foolad, 2007 ). GB is known to accumulate in response to stress in many crop plants, including sugar beet (Beta vulgaris), spinach (Spinacia oleracea), barley (Hordeum vulgare), wheat (Triticum aestivum), and sorghum (Sorghum bicolor).
Some plant species such as rice (Oryza sativa), mustard (Brassica spp.), Arabidopsis (Arabidopsis thaliana) and tobacco (Nicotiana tabacum) naturally do not produce GB under stress or non-stress conditions ( Rhodes and Hanson, 1993). Although Oryza sativa is closely related to poaceous species such as maize, wheat, sorghum, and barley which are able to accumulate GB during encountering stressed environments (Hanson and Scott, 1980; Lerma et al. 1991; Ishitani et al. 1993; Jagendorf and Takabe, 2001; Yang et al. 2003). It is postulated that the endogenous rice Choline Monooxygenase (CMO) gene might be functionless and unable to effectively convert choline into betaine aldehyde (Luo et al. 2012; Yu et al. 2014).
Even absence of glycine betaine in Oryza sativa, this pathway will help in curation for projected species.