Insights into Seasonal Dormancy of Perennial Herbaceous Forages

Abstract

Seasonal dormancy is an adaptive mechanism where plants suspend growth and become physiologically inactive to avoid extreme environmental conditions. Environmental factors like temperature, photoperiod, nutrients, and soil moisture control plant growth and development through various complex molecular mechanisms. Crown and seed dormancy of plants are mostly influenced by day length and temperature. Genes and physiological pathways triggered by these two factors along with genotype variability are some targets to manipulate seasonal dormancy. There is genetic variation in the depth and duration of seasonal dormancy. Therefore, their genetic manipulation is possible. Manipulations of summer and fall dormancy are relatively easier compared to winter dormancy because plants require protection of their apical meristem from freezing temperatures and limited water supply. Genetic factors that regulate seed dormancy may also have regulatory role for seasonal dormancy of the maternal plants. Limited genetic and genomic information are available for seasonal dormancy in herbaceous perennial species. Knowledge of genes controlling seasonal dormancy of eudicots, forest trees, and horticultural crops could be interpolated to explore possible dormancy mechanisms in perennial forages. This study reviews current knowledge of seasonal dormancy of herbaceous forages emphasizing the genetic and physiological context that would be valuable to breeders and plant biologists to expand the production season of perennial species by developing non-dormant and semi-dormant cultivars.

Dissecting Key Adaptation Traits in the Polyploid Perennial Medicago sativa Using GBS-SNP Mapping

“…Alfalfa grows best in cool sub-tropical and warm temperate environments (Duke, 1981 ). Growth and yield are remarkably affected by seasonal dormancy and low temperature stress in winter (Adhikari et al, 2017 ).…”

“…Diminishing day length and temperature in fall season are the two major environmental factors triggering physiological dormancy in alfalfa (McKenzie et al, 1988 ; Brummer et al, 2000 ). FD is a strongly expressed trait where certain genotypes exhibit slow growth leading to a short stature and decumbent plant architecture after autumn clipping (Teuber et al, 1998 ; Adhikari et al, 2017 ). In order to assign FD accurately in the field, it is suggested to collect information from multiple locations for least for 2 years (Teuber et al, 1998 ).…”

Cloning, molecular and functional characterization by overexpression in Arabidopsis of MAPKK genes from grapevine (Vitis vinifera)

“…Numerous studies have provided evidence that MAPK cascades play an important role in the transduction of diverse cellular processes when plant cells are exposed to a variety of abiotic and biotic stresses, including drought, salinity, and temperature (both high and low) stress, as well as pathogen attack, and plant hormone response [2,[10][11][12][13][14]. MAPK cascade is also responsible for regulating seed dormancy in cereal such as barley [15].…”

Cloning, molecular and functional characterization by overexpression in Arabidopsis of MAPKK genes from grapevine (Vitis vinifera)

“…Numerous studies have provided evidence that MAPK cascades play an important role in the transduction of diverse cellular processes when plant cells are exposed to a variety of abiotic and biotic stresses, including drought, salinity, and temperature (both high and low) stress, as well as pathogen attack, and plant hormone response [2,[10][11][12][13][14]. MAPK cascade is also responsible for regulating seed dormancy in cereal such as barley [15]. MAPKs [16,17]; tomato contains 89 MAPKKKs, 6 MAPKKs, and 16 MAPKs [18,19].…”