4.3.1 Glycometabolism provides carbon skeleton and energy forC. japonica in drought environment
Carbohydrates can provide carbon skeleton and energy for the growth and
metabolism of organisms and enhance stress resistance. Glycometabolism
is also the center of biological metabolism, which connects the
metabolism of proteins, lipids, nucleic acids, and secondary substances
(Sun et al., 2015). Based on the comparative genome, abundant
glycometabolism-related genes were expanded or positively selected inC. japonica and further contributed to the desiccation tolerance
of C. japonica . The reasons for the improvement in the
desiccation tolerance of C. japonica by carbohydrate may be as
follows: (i) carbohydrates can accumulate and regulate osmotic pressure
and enhance the water retention of cells (Savitch et al., 2000; Wilson
et al., 2001); (ii) carbohydrates can protect biological substances,
such as biofilms and biological macromolecules, to maintain cytoskeletal
integrity in drought environments (Hincha et al., 2002; Saadeldin et
al., 2020); (iii) carbohydrates can produce energy for resistance to
desiccation (Savitch et al., 2000); and (iv) carbohydrates can also be
used as a signal molecule involved in some desiccation resistance
regulation mechanisms (Paul et al., 2008).