Morphological analysis and stage determination of anther development in sorghum [sorghum bicolor (l.) moench)

Authors: LAZA, HAYDEE - Texas Tech University; KAUR-KAPOOT, HARSIMRAN - Texas Tech University; Xin, Zhanguo; Payton, Paxton; Chen, Junping

Submitted to: Planta
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/10/2022
Publication Date: 3/14/2022
Citation: Laza, H.E., Kaur-Kapoot, H., Xin, Z., Payton, P.R., Chen, J. 2022. Morphological analysis and stage determination of anther development in Sorghum [Sorghum bicolor (L.) Moench. Planta. 255. Article 86. https://doi.org/10.1007/s00425-022-03853-y.
DOI: https://doi.org/10.1007/s00425-022-03853-y

Interpretive Summary: Sorghum is an important cereal crop for production in semi-arid and other marginal environments. High temperature stress that most always accompanies drought stress damages plant reproductive tissues and results in decreased yield. In sorghum, the male reproductive tissues, called anthers, and fertility are particularly sensitive to high temperatures. In this study, ARS scientists at Lubbock, Texas and university collaborators examined the cellular changes of sorghum anthers and altered development under high temperature stress. The results showed 18 distinct stages of anther development and significant alterations in several stages in response to high temperature stress that were correlated with decreased fertility. The findings of this study will serve as an important reference for future studies focusing on sorghum physiology, reproductive biology, genetics, and genomics and provide a baseline of anther development data for reference using new, heat tolerant sorghum lines. Improvements in anther heat tolerance will have a direct effect on sorghum yield.

Technical Abstract: Sorghum (Sorghum bicolor L. Moench) is the fifth most important cereal crop in the world. It has relatively high resilience to moisture and high temperature stresses during vegetative growing stages comparing to major cereal crops. However, like other cereal crops, the sensitivity of the male organ to heat and drought can severely depress sorghum yield due to the reduced fertility and pollination efficiency if the stress occurs at reproductive stage. Identifications of the most vulnerable stages and the genes and genetic networks that differentially regulate the abiotic stress responses in anther development are two critical prerequisites for targeted molecular trait selection and in breeding for enhanced environmentally resilient sorghum using a variety of genetic modification strategies. However, in sorghum, anther developmental stages have not been determined. The distinctive cellular characteristics associated with anther development have not been well examined. Lack of such critical information is a major obstacle in the studies of anther and pollen development in sorghum. In this study, we examined the morphological changes of sorghum anthers at the cellular level during the entire male organ development processes using a modified high-throughput imaging variable pressure scanning electron microscopy and the traditional light microscopy methods. We divided sorghum anther into 18 distinctive stages and provided detailed morphological characteristic changes in sorghum anther for each of the stages. The findings of this study will serve as an important reference for future studies focusing on sorghum physiology, reproductive biology, genetics, and genomics.