Gangwar Manali, Sood Archit, Bansal Ankush, Chauhan Rajinder Singh
1Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Waknaghat, Solan, HP 173215 India.
2Present Address: Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur, HP 176061 India.
3 Biotech. 2018 Jan;8(1):64. doi: 10.1007/s13205-018-1089-2. Epub 2018 Jan 12.
The low seed yield of has been a stumbling block in realizing its full potential as an ideal bioenergy crop. Low female to male flower ratio is considered as a major limiting factor responsible for low seed yield in Jatropha. An exogenous cytokinin application was performed on floral meristems to increase the seed yield. This resulted in an increase of total flowers count with a higher female to male flower ratio. However, the seed biomass did not increase in the same proportion. The possible reason for this was hypothesized to be the lack of increased photosynthesis efficiency at source tissues which could fulfil the increased demand of photosynthates and primary metabolites in maturing seeds. After cytokinin application, possible molecular mechanisms underlying carbon capture and flux affected between the source and sink in developing flowers, fruits and seeds were investigated. Comparative transcriptome analysis was performed on inflorescence meristems (treated with cytokinin) and control (untreated inflorescence meristems) at time intervals of 15 and 30 days, respectively. KEGG-based functional annotation identified various metabolic pathways associated with carbon capture and flux. Pathways such as photosynthesis, carbon fixation, carbohydrate metabolism and nitrogen metabolism were upregulated after 15 days of cytokinin treatment; however, those were downregulated after 30 days. Five genes , , , and showed significant increase in transcript abundance after 15 days of treatment but showed a significant decrease after 30 days. These genes, after functional validation, can be suitable targets in designing a suitable genetic intervention strategy to increase overall seed yield in Jatropha.
[植物名称]种子产量低一直是其作为理想生物能源作物充分发挥潜力的绊脚石。雌雄花比例低被认为是麻疯树种子产量低的主要限制因素。为了提高种子产量，对花分生组织进行了外源细胞分裂素处理。这导致总花数增加，雌雄花比例更高。然而，种子生物量并没有以相同的比例增加。据推测，其可能原因是源组织的光合作用效率没有提高，无法满足成熟种子对光合产物和初级代谢产物增加的需求。在施用细胞分裂素后，研究了发育中的花、果实和种子中源库之间碳捕获和通量影响的潜在分子机制。分别在15天和30天的时间间隔对花序分生组织（用细胞分裂素处理）和对照（未处理的花序分生组织）进行了比较转录组分析。基于KEGG的功能注释确定了与碳捕获和通量相关的各种代谢途径。细胞分裂素处理15天后，光合作用、碳固定、碳水化合物代谢和氮代谢等途径上调；然而，30天后这些途径下调。五个基因，[基因名称1]、[基因名称2]、[基因名称3]、[基因名称4]和[基因名称5]在处理15天后转录丰度显著增加，但在30天后显著下降。这些基因经过功能验证后，可能是设计合适的基因干预策略以提高麻疯树整体种子产量的合适靶点。
