title: Regulatory Networks in Pollen Development under Cold Stress.
abstract: Cold stress modifies anthers' metabolic pathways to induce pollen sterility. Cold-tolerant plants, unlike the susceptible ones, produce high proportion of viable pollen. Anthers in susceptible plants, when exposed to cold stress, increase abscisic acid (ABA) metabolism and reduce ABA catabolism. Increased ABA negatively regulates expression of tapetum cell wall bound invertase and monosaccharide transport genes resulting in distorted carbohydrate pool in anther. Cold-stress also reduces endogenous levels of the bioactive gibberellins (GAs), GA4 and GA7, in susceptible anthers by repression of the GA biosynthesis genes. Here, we discuss recent findings on mechanisms of cold susceptibility in anthers which determine pollen sterility. We also discuss differences in regulatory pathways between cold-stressed anthers of susceptible and tolerant plants that decide pollen sterility or viability.
authors.affiliation: Department of Agricultural Biotechnology, Chaudhary Sarwan Kumar Himachal Pradesh Agricultural University Palampur, India.
authors.forename: Kamal D
authors.initials: KD
authors.lastname: Sharma
authors.affiliation: Department of Botany, Panjab University Chandigarh, India.
authors.forename: Harsh
authors.initials: H
authors.lastname: Nayyar
keywords: abscisic acid signaling; anther; bioactive gibberellins; cold stress; pollen development; pollen sterility; sugar metabolism