Transcriptomic response is more sensitive to water deficit in shoots than roots of Vitis riparia (Michx.)

Abstract

Background Drought is an important constraint on grapevine sustainability. Vitis riparia, widely used in rootstock and scion breeding, has been studied in isolated leaf drying response studies; however, it is essential to identify key root and shoot water deficit signaling traits in intact plants. This information will aid improved scion and rootstock selection and management practices in grapevine. RNAseq data were generated from V. riparia roots and shoots under water deficit and well-watered conditions to determine root signaling and shoot responses to water deficit. Results Shoot elongation, photosynthetic rate, and stomatal conductance were significantly reduced in water deficit (WD) treated than in well-watered grapevines. RNAseq analysis indicated greater transcriptional differences in shoots than in roots under WD, with 6925 and 1395 genes differentially expressed, respectively (q-value < 0.05). There were 50 and 25 VitisNet pathways significantly enriched in WD relative to well-watered treatments in grapevine shoots and roots, respectively. The ABA biosynthesis genes beta-carotene hydroxylase, zeaxanthin epoxidase, and 9-cis-epoxycarotenoid dioxygenases were up-regulated in WD root and WD shoot. A positive enrichment of ABA biosynthesis genes and signaling pathways in WD grapevine roots indicated enhanced root signaling to the shoot. An increased frequency of differentially expressed reactive oxygen species scavenging (ROS) genes were found in the WD shoot. Analyses of hormone signaling genes indicated a strong ABA, auxin, and ethylene network and an ABA, cytokinin, and circadian rhythm network in both WD shoot and WD root. Conclusions This work supports previous findings in detached leaf studies suggesting ABA-responsive binding factor 2 ( ABF2 ) is a central regulator in ABA signaling in the WD shoot. Likewise, ABF2 may have a key role in V. riparia WD shoot and WD root. A role for ABF3 was indicated only in WD root. WD shoot and WD root hormone expression analysis identified strong ABA, auxin, ethylene, cytokinin, and circadian rhythm signaling networks. These results present the first ABA, cytokinin, and circadian rhythm signaling network in roots under water deficit. These networks point to organ specific regulators that should be explored to further define the communication network from soil to shoot. Electronic supplementary material The online version of this article (10.1186/s12870-019-1664-7) contains supplementary material, which is available to authorized users.

Plant growth under suboptimal water conditions: early responses and methods to study them

“…1c). The accumulation of Ca 2+ has been reported to occur under salt, mannitol, sorbitol and PEG-mediated osmotic stress and occurs in waves of which the first peak was observed within five seconds following stress exposure (Kiegle et al, 2000;Yuan et al, 2014;Stephan et al, 2016). The Ca 2+ peak is compound-specific (see later) and only lasts for about one minute but repetitive peaks can trigger sustained signals in specific root cell types (Kiegle et al, 2000).…”

“…Osmotic stress triggers molecular and phenotypic changes locally at root level, but the effects in the shoot are even more pronounced (Claeys et al, 2014b;Khadka et al, 2019). Shoot responses to osmotic stress reduce growth, redirect energy metabolism and minimize water loss, requiring a fast and mobile signal from the root to the shoot.…”

Water Deficit Transcriptomic Responses Differ in the Invasive Tamarix chinensis and T. ramosissima Established in the Southern and Northern United States

“…The WRKY genes (18 and 26) are up-regulated in T. chinensis, and WRKY57 is up-regulated in both T. chinensis and T. ramosissima. WRKY57 was also up-regulated in the woody liana Vitis riparia during water deficit, which is a strong potential indication of a role for the WRKY57 transcription factor in water deficit response [54].…”

“…However, NAC103 and NAC47 and peroxidase genes were up-regulated in both T. chinensis and T. ramosissima in response to water deficit. In V. riparia, NAC47 and peroxidase and superoxide dismutase genes are also up-regulated in leaves in response to water deficit [54]. This suggests a potential role for NAC47 and NAC103 and peroxidase regulation in water deficit tolerance [37].…”

Gaining Insight into Exclusive and Common Transcriptomic Features Linked to Drought and Salinity Responses across Fruit Tree Crops

“…The role of ethylene in drought resistance is well known [ 33 , 34 ]. The transgenic induction of ethylene response factor 1 (ERF1) in wheat enhanced resistance to salt and drought stress, inducing an increase in chlorophyll content, as well as superoxide dismutase and peroxidase activity [ 35 ].…”