ABSTRACT
With global climate change, the frequent occurrence of intense rainfall and aggravation of waterlogging disasters have severely threatened the plant growth and fruit quality of grapevines, which are commercially important fruit crops worldwide. There is accordingly an imperative to clarify the responses of grapevine to waterlogging and to propose appropriate remedial measures. Strigolactone (SL) is a phytohormone associated with plant abiotic stress tolerance, while, its function in plant responses to waterlogging stress remain undetermined. In this study, systematic analyses of the morphology, physiology, and transcriptome changes in grapevine leaves and roots under post-waterlogging and GR24 (a synthetic analog of SL) treatments were performed. Morphological and physiological changes in grapevines in response to post-waterlogging stress, including leaf wilting and yellowing, leaf senescence, photosynthesis inhibition, and increased anti-oxidative systems, could be alleviated by the application of GR24. Moreover, transcriptome analysis revealed that the primary gene functions induced by post-waterlogging stress changed over time; however, they were consistently associated with carbohydrate metabolism. The GR24-induced leaf genes were closely associated with carbohydrate metabolism, photosynthesis, antioxidant systems, and hormone signal transduction, which were considered vital aspects that were influenced by GR24 in grapevine to induce post-waterlogging tolerance. Concerning the roots, an enhancement of microtubules and cytoskeleton for cell construction in GR24 application was proposed to facilitate root system recovery after waterlogging. With this study, we comprehend the knowledge regarding the responses of grapevines to post-waterlogging and the ameliorative effect of GR24 with the insight to the transcriptome changes during these processes.
ABSTRACT
This study employed various methods, including recording of phenological phenomena and analysis of physicochemical indicators, to scrutinize effects of strigolactone and abscisic acid on indicators of ripeness, phenolic compounds, and antioxidant activity. 50 µM GR24 (strigolactone analog), 200 µM ABA (abscisic acid), 50 µM GR24 + 200 µM ABA, and 200 µM ABA + 10 µM TIS108 (strigolactone-biosynthesis inhibitor) were employed in E-L34 and E-L35. Samples were collected from E-L34 to E-L38. Each treatment could improve sugar contents and reduce acid contents, especially in the ABA + TIS group whose contents were 1 °brix higher and 1.11 g/L lower than the control group. Additionally, the ABA and ABA + TIS groups could significantly contribute to phenolic accumulation, especially anthocyanins which were increased by at least 1.5 mg/g at each stage. However, the ABA + GR group had some inhibitory effects on ripening. Therefore, this study can lay a foundation for precisely applying exogenous ABA and GR24.
ABSTRACT
Drought stress can significantly affect the growth and yield of grapevine. The application of exogenous strigolactone can relieve the drought symptoms of grapevine; however, little is known about the transcription levels in grapevine under drought stress following exogenous strigolactone application. The mitigative effect of exogenous strigolactone on grapevine leaves under drought stress was studied by transcriptome analysis based on RNA sequencing. On the 10th day of drought stress, the strigolactone treatment group had a higher relative water content and lower electrical conductivity, which significantly alleviated the drought damage. Compared to the drought (D) group, a total of 5955 differentially expressed genes (DEGs) (2966 up-regulated genes and 2989 down-regulated genes) were detected in the exogenous strigolactone (DG) groups. Based on Gene Ontology analysis, the DEGs in the D and DG treatments were enriched in the processes of photosynthesis and organic acid catabolism. Pathway analysis showed that the DEGs in the D and DG treatments were enriched in carbon metabolism, ribosome, starch and sucrose metabolism, flavonoid biosynthesis, and circadian rhythm. Additionally, in the DG group, the antioxidant enzyme genes of CAT1, GSHPX1, GSHPX2, POD42, APX6, and SODCP were up-regulated, two NAC, three WRKY, and four MYB transcription factor genes were down-regulated, and the key gene of strigolactone synthesis D14 was up-regulated, compared with that in the D group. The results provide a new perspective for studying the adaptation of plants to drought stress.
Subject(s)
Droughts , Vitis , Gene Expression Profiling , Heterocyclic Compounds, 3-Ring , Lactones , Plant Proteins/genetics , Plant Proteins/metabolism , Transcriptome , Vitis/genetics , Vitis/metabolismABSTRACT
To clarify the variant complex congenital cardiac defects, Van Praagh introduced a system of segmental sets to classify the majority of congenital heart diseases, but the code system entails some confusion for complete understanding. We attempted to recategorize the variant sets into four subgroups according to the connection of the atrial-ventricular and ventricular-arterial segments. This complexity can simply be grouped into four subgroups with regularities. From a simple table so formed, we can quickly ascertain the hemodynamics and the circulatory physiology, and therefore quickly determine the treatment protocol for variant complex hearts.