Sucrose and starch metabolism during Fargesia yunnanensis shoot growth

Abstract

Bamboo is one of the fastest growing plants in the world, but their shoot buds develop very slowly. Information about the sugar storage and metabolism during the shoot growth is lacking. In the present study, we determined the activity of sucrose and starch metabolizing enzymes during the developmental period of Fargesia yunnanensis from shoot buds to the young culms that have achieved their full height. The soluble sugars and starch contents were also determined and analyzed in shoot buds and shoots at different developmental stages. The results showed that there were higher sucrose contents in shoot buds than shoots, which coincides with the sweeter taste of shoot buds. As the shoot buds sprouted out of the ground, the starch and sucrose were depleted sharply. Coupled with this, the activity of soluble acid invertase (SAI), cell wall‐bound invertase (CWI), sucrose synthase at cleavage direction (SUSYC) and starch phosphorylase (STP) increased significantly in the rapidly elongating internodes. These enzymes dominated the rapid elongation of internodes. The activities of SAI, CWI, SUSYC and STP and adenosine diphosphate‐glucose pyrophosphorylase were higher as compared to other enzymes in the shoot buds, but were far lower than those in the developing shoots. The slow growth of shoot buds was correlated with the low activity of these enzymes. These results complement our understanding of the physiological differences between shoot buds and elongating shoots and ascertain the physiological mechanism for the rapid growth of bamboo shoots.

Physiological Mechanism of Internode Bending Growth After the Excision of Shoot Sheath in Fargesia yunnanensis and Its Implications for Understanding the Rapid Growth of Bamboos

“…Wei et al (2019) reported that sugar plays an important role in promoting bamboo internode elongation. A similar conclusion was also reported by Wang et al (2020), stating that the starch-and sucrose-metabolizing enzymes correlated well with the bamboo internode elongation.…”

“…In order to trace the assimilate transport rates in the phloem of bending internodes, an aqueous working solution of 5,6carboxyfluorescein diacetate (CFDA, Sigma-Aldrich, St. Louis, MO, United States) was prepared by diluting a 1% CFDA stock solution (in acetone, stored at −20 • C) in 10 mM phosphatebuffered saline (PBS, pH 6.8), and the final concentration was about 30 µg ml −1 . The introduction of CFDA was conducted according to the methods of Hancock et al (2008); Milne et al (2015) and Wang et al (2020). The phloem transport rates of the inner and outer sides of the bending internodes were separately determined.…”

Transcriptome analyses provide insights into the homeostatic regulation of axillary buds in upland cotton (G. hirsutum L.)

“…According to our measurements, with cotton plant growth and development, the soluble sugar content of the axillary buds in the two types plants gradually increased, and the soluble sugar contents in HB-E, HB-G1 and HB-G2 were higher than those in LB-E, LB-G1 and LB-G2, respectively. These findings supported the traditional opinion that the bud is a site of the nutrient accumulation and storage and that plants with more buds show more nutrient accumulation [60]. A previous study also indicated that tubers are storage organs that accumulate starch during the development of potato [61].…”

Transcriptome analysis reveals key genes regulating signaling and metabolic pathways during the growth of moso bamboo (Phyllostachys edulis) shoots

“…The sucrose and starch contents decreased significantly as bamboo shoot grew, while the soluble sugar content increased significantly (Figure 9A-C). These results were consistent with the gradual decrease in sweetness that occurs during the growth of moso bamboo shoots, while the increasing soluble sugar content is used for the energy production and substrate synthesis necessary for growth (Wang et al, 2020).…”

“…In the early growth of bamboo shoots, sucrose is continuously degraded into soluble sugars, such as fructose and glucose. Therefore, the sucrose content is continuously decreasing, while the total soluble sugar content is continuously increasing (Wang et al, 2020). The change in the sugar content measured in bamboo shoots (Figure 9A,B), which showed that these DEGs have positive effects on sugar metabolic pathways, was consistent with the previous results.…”