Organisms have evolved effective and distinct adaptive strategies to
survive. Stipa grandis is one of the widespread dominant species
on the typical steppe of the Inner Mongolian Plateau, and is regarded as
a suitable species for studying the effects of grazing in this region.
Although phenotypic (morphological and physiological) variations in
S. grandis in response to long-term grazing have been identified,
the molecular mechanisms underlying adaptations and plastic responses
remain largely unknown. Accordingly, we performed a transcriptomic
analysis to investigate changes in gene expression of S. grandis
under four different grazing intensities. A total of 2,357
differentially expressed genes (DEGs) were identified among the tested
grazing intensities, suggesting long-term grazing resulted in gene
expression plasticity that affected diverse biological processes and
metabolic pathways in S. grandis. DEGs were identified that
indicated modulation of Calvin–Benson cycle and photorespiration
metabolic pathways. The key gene´expression profiles encoding various
proteins (e.g., Ribulose-1,5-bisphosphate carboxylase/oxygenase,
fructose-1,6-bisphosphate aldolase, glycolate oxidase etc.) involved in
these pathways suggest that they may synergistically respond to grazing
to increase the resilience and stress tolerance of S. grandis.
Our findings provide scientific clues for improving grassland use and
protection, and identify important questions to address in future
transcriptome studies.
Transcriptome-wide gene expression plasticity in Stipa grandis in response to grazing intensity differences