Identification of differentially expressed transcripts at critical developmental stages in sorghum [Sorghum bicolor (L.) Moench] in relation to grain yield heterosis

Abstract

Evaluation of a set of 10 F 1 hybrids along with their female (27A and 7A) and male parents (C 43, RS 673, RS 627, CB 26, and CB 29) for grain yield and its component traits revealed that grain yield/plant followed by panicle weight, primary branches/panicle, and 100-seed weight exhibited high levels of heterosis. Eight hybrids exhibited 50% or more mid-parent heterosis for grain yield/plant, of which, one hybrid (27A × RS673) recorded heterobeltiosis above 50% (73.61%). Differential display analysis generated about 2995 reproducible transcripts, which were categorized as UPF 1 -expressed in any one of the parents and F 1 (10.53-14.76%), BPnF 1 -expressed in both parents but not in F 1 (4.56-11.44%), UPnF 1 -expressed in either of the parents and not in F 1 (17.95-27.40%), F 1 nBP-expressed only in F 1 but not in either of the parents (14.39-20.54%), and UET-expressed in both parents and F 1 (34.52-42.43%). A comparison between high and low heterotic hybrids revealed that the proportions of UPF 1 and F 1 nBP transcript patterns were much higher in the former (21.31% and 45.24%) as compared to the latter (16.67% and 32.14%) at the booting and flowering stage, respectively, indicating the role of over-dominance and dominance in the manifestation of grain yield heterosis. Significant positive correlations were observed for differential transcript patterns with mid-parent and better-parent heterosis for the components of grain yield such as primary branches (0.63 and 0.61 at p < 0.01) and 100-seed weight (0.64 and 0.52 at p < 0.01). Cloning and sequence analysis of 16 transcripts that were differentially expressed in hybrids and their parental lines revealed that they code for genes involved in basic cellular processes, cellulose biosynthesis, and assimilate partitioning between various organs and allocation between various pathways, pyrimidine, and polyamine biosynthesis, enhancing ATP production and regulation of plant growth and development.

Genome-wide identification and characterization of the OFP gene family in Chinese cabbage (Brassica rapa L. ssp. pekinensis)

“…The differentially expressed genes in wheat hybrids were involved in important biological pathways such as photosynthesis and carbon fixation, which promoted the formation of heterosis (Liu et al, 2018). The differentially expressed genes in sorghum hybrids were closely related to the formation of grain yield advantage (Jaikishan et al, 2019). B. rapa L. ssp.…”

“…The differentially expressed genes in wheat hybrids are involved in biological pathways including photosynthesis and carbon fixation, which promote the formation of heterosis, when compared to their parents (Liu et al, 2018). The differentially expressed genes in sorghum hybrids are related to the formation of grain yield dominance (Jaikishan et al, 2019). Changes in gene expression levels alter specific physiological and biochemical reactions, which lead to trait changes and the formation of dominant phenotypes.…”