RESUMEN
The yellow-fleshed loquat is abundant in carotenoids, which determine the fruit's color, provide vitamin A, and offer anti-inflammatory and anti-cancer health benefits. In this research, the impact of abscisic acid (ABA), a plant hormone, on carotenoid metabolism and flesh pigmentation in ripening loquat fruits was determined. Results revealed that ABA treatment enhanced the overall content of carotenoids in loquat fruit, including major components like ß-cryptoxanthin, lutein, and ß-carotene, linked to the upregulation of most genes in the carotenoid biosynthesis pathway. Furthermore, a transcription factor, EjWRKY6, whose expression was induced by ABA, was identified and was thought to play a role in ABA-induced carotenoid acceleration. Transient overexpression of EjWRKY6 in Nicotiana benthamiana and stable genetic transformation in Nicotiana tabacum with EjWRKY6 indicated that both carotenoid production and genes related to carotenoid biosynthesis could be upregulated in transgenic plants. A dual-luciferase assay proposed a probable transcriptional control between EjWRKY6 and promoters of genes associated with carotenoid production. To sum up, pre-harvest ABA application could lead to carotenoid biosynthesis in loquat fruit through the EjWRKY6-induced carotenoid biosynthesis pathway.
RESUMEN
Small auxin upregulated RNAs (SAURs) are primary auxin response genes; the function of regulating root growth angle (RGA) is unclear in the apple rootstock. We firstly identified 96 MdSAUR genes families from new apple genome GDDH13 using the resequence database of 'Baleng Crab (BC)' and 'M9'. A total of 25 MdSAUR genes, regulating the formation of RGA, were screened for the expression profiles in stems and roots and the allelic variants of quantitative trait loci (QTL). Finally, through the joint analysis of network and protein-protein interaction, MdSAUR2, MdSAUR29, MdSAUR60, MdSAUR62, MdSAUR69, MdSAUR71, and MdSAUR84 were screened as the main candidate genes for regulating RGA. This study provides a new insight for further revealing the regulatory mechanism of RGA in apple dwarf rootstocks.
Asunto(s)
Ácidos Indolacéticos , Malus , Raíces de Plantas , Regulación de la Expresión Génica de las Plantas , Ácidos Indolacéticos/metabolismo , Malus/genética , Familia de Multigenes , ARN/metabolismo , Raíces de Plantas/crecimiento & desarrolloRESUMEN
Apple (Malus domestica Borkh.) is not only an important fruit crop distributed worldwide, but also a common model plant. However, the lack of efficient genetic transformation procedures for apples limits the in-depth studies of their gene functions. Although leaf-regenerated adventitious shoots (LRAS) are a prerequisite for successful genetic transformation of apple, little is known about the underlying molecular mechanism of LRAS. Here, we identified the WUSCHEL-related homeobox (WOX) transcription factor in apple, MdWOX4-2, which was a transcriptional activator. Gene expression as well as morphological and histological observations revealed that MdWOX4-2 is involved in the development of LRAS. Overexpression of MdWOX4-2 conferred higher regenerative capacity in transgenic tobacco (Nicotiana tabacum) as compared to the wild type (WT). The combined results of the yeast one-hybrid (Y1H), electrophoretic mobility shift assay (EMSA), dual luciferase assays, and transient transactivation assay, revealed that MdWOX4-2 directly bound to and activated the MdLBD41 promoter. Moreover, transgenic experiments further demonstrated that MdLBD41 could significantly enhance the formation of adventitious shoot in transgenic tobacco. Collectively, our findings demonstrate that MdWOX4-2 is important for regulating the LRAS development by activating MdLBD41.
Asunto(s)
Malus , Frutas/metabolismo , Regulación de la Expresión Génica de las Plantas , Malus/metabolismo , Hojas de la Planta/genética , Hojas de la Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Nicotiana/genética , Nicotiana/metabolismo , Factores de Transcripción/genéticaRESUMEN
Virtual reality (VR) video streaming (a.k.a., 360-degree video streaming) has been gaining popularity recently as a new form of multimedia providing the users with immersive viewing experience. However, the high volume of data for the 360-degree video frames creates significant bandwidth challenges. Research efforts have been made to reduce the bandwidth consumption by predicting and selectively streaming the user's viewports. However, the existing approaches require historical user or video data and cannot be applied to live streaming, the most attractive VR streaming scenario. We develop a live viewport prediction mechanism, namely LiveObj, by detecting the objects in the video based on their semantics. The detected objects are then tracked to infer the user's viewport in real time by employing a reinforcement learning algorithm. Our evaluations based on 48 users watching 10 VR videos demonstrate high prediction accuracy and significant bandwidth savings obtained by LiveObj. Also, LiveObj achieves real-time performance with low processing delays, meeting the requirement of live VR streaming.