Moderate drought causes dramatic floral transcriptomic reprogramming to ensure successful reproductive development in Arabidopsis
1 Department of Biology and the Huck Institutes of the Life Sciences, the Pennsylvania State University, University Park, State College, PA 16802, USA
2 Intercollege Graduate Program in Cell and Developmental Biology, the Pennsylvania State University, University Park, State College, PA 16802, USA
3 State Key Laboratory of Genetic Engineering and Institute of Plant Biology, Institute of Genetics, Center for Evolutionary Biology, School of Life Sciences, Fudan University, Shanghai 200433, China
4 Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
5 Current address: School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia
BMC Plant Biology 2014, 14:164 doi:10.1186/1471-2229-14-164Published: 13 June 2014
Drought is a major constraint that leads to extensive losses to agricultural yield worldwide. The potential yield is largely determined during inflorescence development. However, to date, most investigations on plant response to drought have focused on vegetative development. This study describes the morphological changes of reproductive development and the comparison of transcriptomes under various drought conditions.
The plants grown were studied under two drought conditions: minimum for successful reproduction (45-50% soil water content, moderate drought, MD) and for survival (30-35%, severe drought, SD). MD plants can produce similar number of siliques on the main stem and similar number of seeds per silique comparing with well-water plants. The situation of SD plants was much worse than MD plants. The transcriptomes of inflorescences were further investigated at molecular level using microarrays. Our results showed more than four thousands genes with differential expression under severe drought and less than two thousand changed under moderate drought condition (with 2-fold change and q-value < 0.01). We found a group of genes with increased expression as the drought became more severe, suggesting putative adaptation to the dehydration. Interestingly, we also identified genes with alteration only under the moderate but not the severe drought condition, indicating the existence of distinct sets of genes responsive to different levels of water availability. Further cis-element analyses of the putative regulatory sequences provided more information about the underlying mechanisms for reproductive responses to drought, suggesting possible novel candidate genes that protect those developing flowers under drought stress.
Different pathways may be activated in response to moderate and severe drought in reproductive tissues, potentially helping plant to maximize its yield and balance the resource consumption between vegetative and reproductive development under dehydration stresses.