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  - 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  -