TY - JOUR A1 - Medini, Wided A1 - Farhat, Nejia A1 - Al-Rawi, Shadha A1 - Mahto, Harendra A1 - Qasim, Hadeel A1 - Ben-Halima, Emna A1 - Bessrour, Mouna A1 - Chibani, Farhat A1 - Abdelly, Chedly A1 - Fettke, Jörg A1 - Rabhi, Mokded T1 - Do carbohydrate metabolism and partitioning contribute to the higher salt tolerance of Hordeum marinum compared to Hordeum vulgare? JF - Acta Physiologiae Plantarum N2 - The aim of the present work was to check whether carbohydrate metabolism and partitioning contribute to the higher salt tolerance of the facultative halophyte Hordeum marinum compared to the glycophyte Hordeum vulgare. Seedlings with the same size from the two species were hydroponically grown at 0 (control), 150, and 300 mM NaCl for 3 weeks. H. marinum maintained higher relative growth rate, which was concomitant with a higher aptitude to maintain better shoot tissue hydration and membrane integrity under saline conditions compared to H. vulgare. Gas exchanges were reduced in the two species under saline conditions, but an increase in their water use efficiency was recorded. H. marinum exhibited an increase in leaf soluble sugar concentrations under saline conditions together with an enhancement in the transglucosidase DPE2 (EC 2.4.1.25) activity at 300 mM NaCl. However, H. vulgare showed a high increase in starch phosphorylase (EC 2.4.1.1) activity under saline conditions together with a decrease in leaf glucose and starch concentrations at 300 mM NaCl. In roots, both species accumulated glucose and fructose at 150 mM NaCl, but H. marinum exhibited a marked decrease in soluble sugar concentrations and an increase in starch concentration at 300 mM NaCl. Our data constitute an initiation to the involvement of carbohydrate metabolism and partitioning in salt responses of barley species and further work is necessary to elucidate how their flexibility confers higher tolerance to H. marinum compared to H. vulgare. KW - Cultivated barley KW - DPE2 KW - Flexibility KW - Pho1 KW - Pho2 KW - Sea barley Y1 - 2019 U6 - https://doi.org/10.1007/s11738-019-2983-x SN - 0137-5881 SN - 1861-1664 VL - 41 IS - 12 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Malinova, Irina A1 - Mahto, Harendra A1 - Brandt, Felix A1 - AL-Rawi, Shadha A1 - Qasim, Hadeel A1 - Brust, Henrike A1 - Hejazi, Mahdi A1 - Fettke, Jörg T1 - EARLY STARVATION1 specifically affects the phosphorylation action of starch-related dikinases JF - The plant journal N2 - Starch phosphorylation by starch-related dikinases glucan, water dikinase (GWD) and phosphoglucan, water dikinase (PWD) is a key step in starch degradation. Little information is known about the precise structure of the glucan substrate utilized by the dikinases and about the mechanisms by which these structures may be influenced. A 50-kDa starch-binding protein named EARLY STARVATION1 (ESV1) was analyzed regarding its impact on starch phosphorylation. In various invitro assays, the influences of the recombinant protein ESV1 on the actions of GWD and PWD on the surfaces of native starch granules were analyzed. In addition, we included starches from various sources as well as truncated forms of GWD. ESV1 preferentially binds to highly ordered, -glucans, such as starch and crystalline maltodextrins. Furthermore, ESV1 specifically influences the action of GWD and PWD at the starch granule surface. Starch phosphorylation by GWD is decreased in the presence of ESV1, whereas the action of PWD increases in the presence of ESV1. The unique alterations observed in starch phosphorylation by the two dikinases are discussed in regard to altered glucan structures at the starch granule surface. KW - Arabidopsis thaliana KW - EARLY STARVATION1 KW - glucan KW - phosphoglucan KW - starch granule surface KW - starch phosphorylation KW - water dikinase Y1 - 2018 U6 - https://doi.org/10.1111/tpj.13937 SN - 0960-7412 SN - 1365-313X VL - 95 IS - 1 SP - 126 EP - 137 PB - Wiley CY - Hoboken ER - TY - GEN A1 - Malinova, Irina A1 - Qasim, Hadeel M. A1 - Brust, Henrike A1 - Fettke, Jörg T1 - Parameters of Starch Granule Genesis in Chloroplasts of Arabidopsis thaliana T2 - Frontiers in Plant Science N2 - Starch is the primary storage carbohydrate in most photosynthetic organisms and allows the accumulation of carbon and energy in form of an insoluble and semi-crystalline particle. In the last decades large progress, especially in the model plant Arabidopsis thaliana, was made in understanding the structure and metabolism of starch and its conjunction. The process underlying the initiation of starch granules remains obscure, although this is a fundamental process and seems to be strongly regulated, as in Arabidopsis leaves the starch granule number per chloroplast is fixed with 5-7. Several single, double, and triple mutants were reported in the last years that showed massively alterations in the starch granule number per chloroplast and allowed further insights in this important process. This mini review provides an overview of the current knowledge of processes involved in the initiation and formation of starch granules. We discuss the central role of starch synthase 4 and further proteins for starch genesis and affecting metabolic factors. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 478 KW - starch biosynthesis KW - starch granule biogenesis KW - starch synthase KW - plastidial phosphorylase KW - maltooligosaccharides Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-419295 UR - urn:nbn:de:kobv:517-opus4-419295 ER - TY - JOUR A1 - Malinova, Irina A1 - Qasim, Hadeel M. A1 - Brust, Henrike A1 - Fettke, Jörg T1 - Parameters of Starch Granule Genesis in Chloroplasts of Arabidopsis thaliana JF - Frontiers in Plant Science N2 - Starch is the primary storage carbohydrate in most photosynthetic organisms and allows the accumulation of carbon and energy in form of an insoluble and semi-crystalline particle. In the last decades large progress, especially in the model plant Arabidopsis thaliana, was made in understanding the structure and metabolism of starch and its conjunction. The process underlying the initiation of starch granules remains obscure, although this is a fundamental process and seems to be strongly regulated, as in Arabidopsis leaves the starch granule number per chloroplast is fixed with 5-7. Several single, double, and triple mutants were reported in the last years that showed massively alterations in the starch granule number per chloroplast and allowed further insights in this important process. This mini review provides an overview of the current knowledge of processes involved in the initiation and formation of starch granules. We discuss the central role of starch synthase 4 and further proteins for starch genesis and affecting metabolic factors. KW - starch biosynthesis KW - starch granule biogenesis KW - starch synthase KW - plastidial phosphorylase KW - maltooligosaccharides Y1 - 2018 U6 - https://doi.org/10.3389/fpls.2018.00761 SN - 1664-462X VL - 9 SP - 1 EP - 7 PB - Frontiers Media CY - Lausanne ER -