Transcriptional Signatures in Contrasting Cultivars of Barley During Early Reproductive Development of Meristem.

Growth and development of meristem in Barley are a result of complex regulatory networks and well-coordinated transcriptional reprogramming modulated by hormonal, photoperiod, nutrient availability, and genetic makeup of cultivars. A critical double ridge stage attained by meristems during phase transitions of vegetative meristems to inflorescence meristem has a significant role in developing the number of spikelets and seeds in lateral stages of plant growth and final crop yield. The early development of meristems leads to attaining early critical stages of phenology and plant growth, completing plant ontogeny in a shorter time displays a heat escaping mechanism to avoid the effects of terminal heat stress on crop growth and yield. In the current study, our results led us to identify a set of tolerant (RD2715, DWRB64) and sensitive (BW902, K508 and GP) contrasting cultivars to terminal heat stress conditions. Tolerant cultivars exhibit a heat escaping mechanism to avoid increasing temperatures by developing and flowering early. The sensitive cultivars are susceptible to terminal heat stress conditions with late development and flowering. This study assessed developing IM tissues at double ridge stage of two contrasting cultivars, RD2715 and GP. Transcriptome data revealed a massive transcriptional reprogramming associated with meristem development accompanied by a set of uniquely expressed transcription factors, possible candidates for early and faster development of meristem. The regulation and development in GP are much slower than RD2715 at the same developmental stage, and they differ in their transcriptional regulation and developmental pace. This study may further expand our understanding of inflorescence development. [ABSTRACT FROM AUTHOR]