Seed development of Jatropha curcas L. (Euphorbiaceae): integrating anatomical, ultrastructural and molecular studies
This work provides a detailed histological analysis of the development of Jatropha curcas seeds, together with an assessment of the role of programmed cell death in this process.
Seeds of Jatropha curcas are a potential source of raw material for the production of biodiesel, but very little is known about how the architecture of the seeds is shaped by the coordinated development of the embryo, endosperm and maternal tissues, namely integuments and nucellus. This study used standard anatomical and ultrastructural techniques to evaluate seed development and programmed cell death (PCD) in the inner integument was monitored by qPCR. In these studies, we found that the embryo sac formation is of the Polygonum type. We also found that embryogenesis is a slow process and the embryo is nourished by the suspensor at earlier stages and by nutrients remobilized from the lysis of the inner integument at later stages. Two types of programmed cell death contribute to the differentiation of the inner integument that begins at early stages of seed development. In addition, the mature embryo presents features of adaptation to dry environments such as the presence of four seminal roots, water absorbing stomata in the root zone and already differentiated protoxylem elements. The findings in this study fill in gaps related to the ontogeny of J. curcas seed development and provide novel insights regarding the types of PCD occurring in the inner integument.
KeywordsJatropha curcas Oilseeds Programmed cell death Ricinosomes Root stomata Seminal roots
We thank Laboratório Temático de Microscopia Óptica e Eletrônica (LTMOE) at Instituto Nacional de Pesquisas da Amazônia (Manaus, Brazil) for the assistance with electron microscopy analysis, Central Analítica/UFC for the support with confocal microscopy, EMBRAPA Agroindústria Tropical/Fortaleza for the support with scanning electron microscopy. This work was supported by Fundação Cearense de Apoio ao Desenvolvimento Científico e Tecnológico (Grant no. BFP-1810026-00898.0l.00/05) and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior and Conselho Nacional de Desenvolvimento Científico e Tecnológico (Grant no. 405936/2013-3).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
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