-Chemical studies of the plant family Annonaceae have intensified in the last several decades due to the discovery of annonaceous molecules with medicinal potential (e.g., benzylisoquinoline alkaloids and acetogenins). Approximately 500 alkaloids have been identified in 138 Annonaceae species in 43 genera. In addition, until 2004, 593 annonaceous acetogenins (ACGs) had been identified, from 51 species in 13 genera.This suggests that plants from this family allocate important resources to the biosynthesis of these compounds. Despite the diversity of these molecules, their biological roles, including their physiological and/ or ecological functions, are not well understood. In this study, it was provided new data describing the variety and distribution of certain alkaloids and ACGs in annonaceous plants in distinct stages of development. The potential relationships among some of these compounds and the seasonally climatic changes occurring in the plant habitat are also discussed. These data will improve our understanding of the secondary metabolism of these pharmacologically important molecules and their expression patterns during development, which will help to determine the optimal growth conditions and harvest times for their production. Index terms: early development, secondary metabolism, ecological functions, phenology. ALCALOIDES E ACETOGENINAS NO DESENVOLVIMENTO DE ANNONACEAE: CONSIDERAÇÕES BIOLÓGICASRESUMO -Estudos químicos em plantas da família Annonaceae se intensificaram nas últimas décadas, devido à descoberta de moléculas de anonáceas com potencial medicinal (por exemplo, alcalóides benzilisoquinolina e acetogeninas). Aproximadamente 500 alcaloides têm sido identificados em 138 espécies de Annonaceae em 43 gêneros. Além disso, até 2004, 593 acetogeninas de annonaceas (ACGs) foram identificados, a partir de 51 espécies em 13 gêneros. Isto sugere que as plantas desta família atribuem recursos importantes para a biossíntese destes compostos. Apesar da diversidade destas moléculas, suas funções biológicas, incluindo as suas funções fisiológicas e/ou ecológicas, não são bem compreendidas. Neste estudo, foram fornecidos novos dados que descrevem a variedade e a distribuição de certos alcaloides e ACGs em annonaceas em fases distintas de desenvolvimento. As possíveis relações entre alguns destes compostos e as alterações climáticas sazonais ocorrendo no habitat são também discutidas. Estes dados vão melhorar a nossa compreensão do metabolismo secundário dessas moléculas farmacologicamente importantes e seus padrões de expressão durante o desenvolvimento, o que ajudará a determinar as condições ideais de crescimento e épocas de colheita para a sua produção. Termos para indexação: desenvolvimento inicial, metabolismo secundário, funções ecológicas, fenologia.

This review aims to present advances in studies on the propagation of the Annonaceae species, which includes species of economic importance such as: soursop, custard apple, atemoya and cherimoya. In sexual propagation, advances are mainly related to a better understanding of the stages of seed development, dormancy mechanisms, and germination. In asexual propagation, compatibility studies between grafts and rootstocks are presented, focusing on the expression of genes involved in tissue formation. The cutting method is also discussed, which is another option for the propagation for this group of plants considered difficult to root, approaching endogenous and exogenous factors related to the subject, as well as management strategies that affect the success of this technique.

Some Annonaceae seeds are known to exhibit dormancy mechanisms ranging from possible seed coat impermeability to physiological dormancy. Thus, the aim of this study was to evaluate the effects of gibberellin (GA) GA3 and GA4+7 + benzyladenine (GA4+7 + BA) application in seeds of Annona macroprophyllata Donn. Sm (papausa) and Annona purpurea Moc. & Sessé ex Dunal (chincuya). The experiment was performed by the application of GA3 and GA4+7 + BA on seeds in concentrations of 0, 200, 400, 500, 600, 800 and 1000 mg L-1. The regulators broke the dormancy of both species. However, application of the GA4+7 + BA mixture had more significant results, with greater increases in germination in A. macroprophyllata than in A. purpurea. Treatments that promoted the highest germinations were GA4+7 + BA at a concentration of 200 mg L-1 for A. macroprophyllata (77%) and 200 mg L-1 of GA4+7 + BA and 500 mg L-1 of GA3 for A. purpurea (30% and 29%, respectively). Rate index, mean time and frequency of germination were distinct for both species and both treatments. Although both GA3 and GA4+7 + BA promote germination, the GA4+7 + BA mixture was more effective than GA3 to overcoming seed dormancy of both species, A. purpurea has a harder dormancy than A. macroprophyllata

Annona purpurea grows in the areas of low elevation in deciduous forests of Mexico, those areas have marked rainy and dry seasons. This species produces more than 30 bioactive alkaloids that could have potential in the control of phytopathogens. This research provides data on the variation of the content and number of alkaloids during an annual cycle and the associated inhibitory potential of the compounds against three phytopathogenic fungi. For one year, alkaloidal extracts of stems and leaves were obtained every two months. The extract profiles were determined by gas chromatography with tandem mass spectrometry and their antifungal activity was examined in vitro. The alkaloids, annomontine and oxopurpureine, obtained from the roots and leaves, respectively, were also evaluated individually. The yields, profiles and activities of the extracts, as well as the abundance of annomontine and oxopurpureine in the extracts, were contrasted with the seasonality and phenological phases of the plant. The data indicate that the alkaloid content was higher at the height of the dry season. High yields also occurred during flowering. The strongest inhibitory effect was obtained from the root extracts during the last month of dry season. This finding seems to be explained by the higher chemodiversity of alkaloids in extracts from this season. Annomontine and oxopurpureine inhibited all three phytopathogens; however, they were not solely responsible for the activity of A. purpurea.

The concentration of nitrogen can generate different strategies in plants in response to stress. In this study, we investigated how nitrogen concentration interferes with the defense system of Annona emarginata . Low concentrations of nitrogen increased the allocation of photosynthetic resources to carbon metabolism, resulting in an increase in the synthesis of volatile substances involved in signaling and defense that contributed to antioxidant enzymes in overcoming stress. The availability of nitrogen at 5.62 mM concentration might have helped to induce increased resistance in the plants because at this concentration, signaling substances and defense substances (monoterpenes and sesquiterpenes) were observed. Plants cultivated with the highest nitrate concentration displaced energy for the reduction of this ion, likely forming nitric oxide, a signaling molecule. This condition, together with the decrease in carbon skeletons, may have contributed to the lower synthesis of volatile substances of the specialized metabolism that are also involved with signaling. Varying the nitrogen in Annona emarginata cultivation revealed that depending on the concentration, volatile substances show higher or lower synthesis and participation in the system of signaling and defense in the plant. These results may suggest that volatile substances participate in resistance to pests and diseases, which is a necessary condition for Annona emarginata to be preferentially used as rootstock for Annona x atemoya .