Abstract
ABSTRACT
Modern sugarcane cultivars are vegetatively propagated interspecific hybrids developed by extensive breeding and selection method to enhance sugar content, culm dimensions, desired plant architecture and disease resistance. Internode length greatly varies among existing sugarcane cultivars which determines culm length, biomass and sugar storage. Molecular factors responsible for this trait remains largely unknown in sugarcane. In this study, we characterized short and long internode sugarcane varieties and elucidated gene regulatory module interplaying with hormonal-network underneath the internodal growth. The genome size, pigment content and juice characteristics of short and long internode varieties differed with each other and corelated with gene expressions pattern. We established tissue and spatial transcriptome dataset, and comparative analyses demonstrated number of genes involved in cell cycle, cell expansion, transcription factors and hormone pathway including
bZIP16
are differentially expressed between short and long internode varieties. Biochemical, DNA-protein interactions and molecular evidences revealed that ScbZIP16 inversely related to GA content by repressing transcripts of
ent
-
isokaurene C2/C3-hydroxylase
and
GA20 Oxidase
in sugarcane. The further genetic evidences confirmed role of
ScbZIP16
in reducing GA biosynthesis pathway, flowering time and growth in
Arabidopsis
. This report of
ScbZIP16
regulatory module offers a potential candidate for sugarcane improvement programs.
Summary Statement
In this study, we found that Sugarcane
bZIP16
as a critical candidate for modulating GA biosynthesis which inversely regulates the internode length in sugarcane.