Abstract
Stylosanthes species are economically important tropical and subtropical forage legumes which are generally vulnerable to chilling and frost. Fine-stem stylo (S. guianensis var. intermedia) has the most superior cold tolerance among all stylo species. A REVEILLE (RVE) gene, SgRVE6, was cloned from fine-stem stylo. Bioinformatic analysis suggests that SgRVE6 encodes a transcription factor of 292 amino acid residues, which belongs to the LATE ELONGATED HYPOCOTYL/CIRCADIAN CLOCK ASSOCIATED 1-LIKE (LCL) subgroup of RVE family and contains a SHAQKYF-class MYB domain and a LCL domain. SgRVE6 is universally expressed in root, stem and leaf tissues of fine-stem stylo and is rapidly up-regulated in all tested tissues under cold stress. Over-expressing SgRVE6 affects expression of 21 circadian clock genes, up-regulates expression of 6 nucleotide binding domain leucine-rich repeats (NB-LRR) encoding genes associated with tobacco cold tolerance, improves physiological responses to low temperature, and endows the transgenic tobaccos with higher tolerance to cold stress. This is the first time a study investigates the biological function of RVE6 in cold responses of plant species.
Highlights
Stylo (Stylosanthes guianensis) is an economically important forage and pasture legume widely cultivated throughout tropical, subtropical and temperate regions of Asia, Africa, Americas and Australia (Noble et al, 2000)
The results revealed that a gene encoding a REVEILLE (RVE) transcription factor was remarkably over-expressed under cold condition and selected as the candidate gene for the study of cold tolerance in fine-stem stylo
Percent identities between SgRVE6 and other leguminous RVE6 proteins ranged from 73% to 92%
Summary
Stylo (Stylosanthes guianensis) is an economically important forage and pasture legume widely cultivated throughout tropical, subtropical and temperate regions of Asia, Africa, Americas and Australia (Noble et al, 2000). Stylo is well adapted to drought and soil infertility, but very vulnerable to low temperature and frost, which is the major factor limiting its growth and survival in subtropical and temperate regions (Zhou et al, 2005; Bao et al, 2016). Fine-stem stylo is well adapted to drought, infertility and low-grazing (persisting after being grazed close to ground for months), but most remarkably fine-stem stylo has the best cold and frost tolerance among all stylo varieties and cultivars. Unveiling the molecular mechanisms underlying the superior cold tolerance of fine-stem stylo will greatly contribute to breeding cold and frost tolerant stylos
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
