DOI: 10.5061/dryad.612jm64hd
title: Accelerated flowering and differential florigen gene expression of seagrass Zostera marina under experimental warming

description: Flowering is an important trait for the resilience of marine angiosperms
 (seagrasses) as they face rising seawater temperatures, more frequent
 extreme weather events, and anthropogenic disturbances. Using the
 seagrass Zostera marina, we applied a common garden approach to
 experimentally test how flowering and its underlying molecular mechanisms
 responded to elevated water temperature (+3°C). We focused on
 developmental and reproductive traits paired with florigen gene expression
 to gain insight to the molecular mechanism underpinning differences in
 flowering responses. We compared annual seedlings from two source
 populations (Willapa Bay along the coast, and Padilla Bay in the Salish
 Sea, Washington, USA) to understand natural variation not only in
 morphological and reproductive traits, but also the gene-environment
 interactions governing flowering onset. At the individual and
 population levels, annual seedlings in the +3°C heated treatment produced
 more spathes and accelerated development of inflorescences so seeds
 dispersed sooner. Seedlings from Padilla Bay flowered at greater rates and
 earlier than Willapa Bay, and these differences were exaggerated by the
 +3°C heated treatment. A predicted repressor of flowering onset,
 ZmaFT9, was expressed at lower levels in the shoots grown in the +3°C
 heated treatment, and even more so in the Padilla Bay population, which
 flowered earlier than the Willapa Bay population. For two predicted floral
 activators, ZmaFT2 and ZmaFT4, expression increased throughout the summer
 regardless of population and showed no response to the temperature
 treatment. ZmaTFL1a, a gene predicted to be involved with downstream
 flowering processes, showed no significant response to the temperature
 treatment.  Together, these results support a key role for
 antiflorigen (ZmaFT9) in the molecular control of flowering in Z. marina,
 and ZmaFT9 expression contributes to the temperature-based response of
 timing of flowering onset. Impacts of elevated seawater temperature on
 flowering timing and spathe production, with different responses by
 population, have potential consequences for seed yield and variation in
 meadow resilience.
description: # Accelerated flowering and differential florigen gene expression of
 seagrass Zostera marina under experimental warming Dataset DOI:
 [10.5061/dryad.612jm64hd](10.5061/dryad.612jm64hd) ## Description of the
 data and file structure This dataset contains the data and code required
 for analyses in Nolan et al. (in review). This dataset includes
 morphological data, flowering phenotype data, and quantitative RT-PCR data
 for gene expression analyses of eelgrass samples. All samples were
 collected from mesocosm tanks at Shannon Point Marine Center (SPMC) in
 Anacortes WA. Shoots and seedlings used were originally collected from
 Padilla Bay, WA and Willapa Bay, WA USA. ### Files and variables ####
 File: SPMC-AnnualTransplantExp2025-GeneExpData.xlsx **Description:** qPCR
 data from annual eelgrass shoots collected from Willapa Bay Washington.
 Data summary on “Readme” sheet within file. ##### Variables * Date:
 collection date of samples, month/day/year * Pop: Population (JL = Joe
 Leary/Padilla Bay, WB = Willapa Bay) * Sample_ID: Sample unique ID
 (includes date, tank, population, and heat treatment) * Pop_Temp:
 Population and temperature treatment * Temp: Temperature treatment
 (Ambient or Heated) * deltaCt: value calculated from Cq value * DevState:
 developmental/reproductive state (F = flowering, V = vegetative, B =
 bolted) * Tank: Tank in the experiment (Ambient = 1,4,6,7; Heated =
 2,3,5,8) #### File: A3_FieldTemps.csv **Description:** Temperature data
 from environmental sensors deployed at intertidal field sites where source
 populations were collected ##### Variables * Date_Time: Date and timestamp
 for the record in month/day/year 24 h time * Temp_C: Temperature
 (Celsius). Note: Temperatures are water and air temperatures depending on
 tidal stage at these intertidal sites. * Site: Embayment where data were
 collected, Willapa Bay or Padilla Bay #### File:
 A3_Molecular_Morphology2024.csv **Description:** Morphological data from
 destructive samples used for molecular analyses from manipulative
 experiment ##### Variables * date_col: Date sample was collected from
 mesocosm experiment * tank: Tank number from which plant was collected *
 trt: Treatment, heated (H) or ambient (A) * site: Source location for
 population, either Willapa Bay (WB) or Padilla Bay (JL) * smpl: individual
 shoot number * stage: Developmental stage of seedling collected, either
 non-flowering (N), flowering (F), or bolted (B) * branches: Number of
 branches connected to the plant individual collected * slength: Length of
 plant to tip of longest leaf, in cm * swidth: Width of plant at sheath, in
 mm * spathes: Number of spathes on the shoot (flowering shoots only) *
 leaf_quanity: Number of leaves on the shoot (non-flowering shoots only) *
 cat0: On flowering shoots only: Number of spathes with undeveloped flowers
 * cat1: On flowering shoots only: Number of spathes with stigma erect *
 cat2: On flowering shoots only: Number of spathes with styles bent back *
 cat3: On flowering shoots only: Number of spathes with anthers dehiscing *
 cat4: On flowering shoots only: Number of spathes with ripening fruits *
 cat5: On flowering shoots only: Number of spathes with seeds dispersed *
 rhlength: Rhizome length, in mm * rtlength: Longest length of bundle of
 roots on rhizome, in cm * internodes: Number of rhizome internodes ####
 File: A3_Transplant_Counts_Compiled.csv **Description:** Census data for
 counts of flowering and non-flowering in each mesocosm tank and tub #####
 Variables * date: Date of census as month/day/year * label: Tub label,
 consisting of site code and tank replicate number * site: Source location
 for population, either Willapa Bay (WB) or Padilla Bay (JL) * tank: Tank
 replicate number * trt: Treatment, heated (heat) or ambient (amb) *
 flwr: Number of flowering shoots counted in the tub * non_flwr: Number of
 non-flowering shoots counted in the tub * total_shoots: Total number of
 shoots counted in the tub (flowering + non-flowering * Other
 abbreviations: NA represents missing data #### File:
 A3_TempLoggersCompiled.csv **Description:** Temperature data from Onset
 Hobo Tidbit loggers placed in each experimental mesocosm tank throughout
 the duration of the manipulative experiment, in wide format #####
 Variables * DateTime: Date and timestamp for the record in month/day/year
 24 h time * T1: Tank 1 temperature data (Celsius) * T2: Tank 2 temperature
 data (Celsius) * T3: Tank 3 temperature data (Celsius) * T4: Tank 4
 temperature data (Celsius) * T5: Tank 5 temperature data (Celsius) *
 T6: Tank 6 temperature data (Celsius) * T7: Tank 7 temperature data
 (Celsius) * T8: Tank 8 temperature data (Celsius) * AIR: Air temperature
 data (Celsius) #### File: A3_Transplant_Morph_Compiled.csv
 **Description:** Non-destructive morphological data from manipulative
 experiment conducted in mesocosms ##### Variables * date: Date of census *
 tub: Tub label, consisting of site code and tank replicate number *
 site: Source location for population, either Willapa Bay (WB) or Padilla
 Bay (JL) * tank: Tank replicate number * trt: Treatment, heated (heat) or
 ambient (amb) * smpl: individual shoot number * stage: Developmental stage
 of seedling, either non-flowering (veg) or flowering (flwr) *
 length: Shoot length to tip of longest leaf, in cm * width: Width of shoot
 at the sheath, in mm * leaves: Number of leaves on the shoot
 (non-flowering shoots only) * spathes: Number of spathes on the shoot
 (flowering shoots only) * cat0: On flowering shoots only: Number of
 spathes with undeveloped flowers * cat1: On flowering shoots only: Number
 of spathes with stigma erect * cat2: On flowering shoots only: Number of
 spathes with styles bent back * cat3: On flowering shoots only: Number of
 spathes with anthers dehiscing * cat4: On flowering shoots only: Number of
 spathes with ripening fruits * cat5: On flowering shoots only: Number of
 spathes with seeds dispersed * cat6: On flowering shoots only: Number of
 spathes post-dispersal #### ## Code/software #### File:
 spmc-geneexp-GAM_02.R **Description:** R code used to generate GAMM for
 gene expression data. Statistical models were built in R version 4.4.2 (R
 Core Team, 2024) using *gam* function from the package *mgcv*. #### File:
 AnnualTransplantExpt2024.R **Description:** R script containing
 visualization and analyses conducted for population and morphological
 level data from manipulative experiment, using R version 4.4.2
 (2024-10-31)