The Dynamic Assimilation Technique measures photosynthetic CO2 response curves with similar fidelity as steady-state approaches in half the time

The net CO2 assimilation (A) response to intercellular CO2 concentration (Ci) is a fundamental measurement in photosynthesis and plant physiology research. The conventional A/Ci protocols rely on steady-state measurements and take 15-40 minute per measurement, limiting data resolution or biological replication. Additionally, there are several CO2 protocols employed across the literature, without clear consensus as to the optimal protocol or systematic biases in their estimations. We compared the non-steady state Dynamic Assimilation Technique (DAT) protocol and the three most used CO2 protocols in steady-state measurements, and tested whether different CO2 protocols lead to systematic differences in estimations of the biochemical limitations to photosynthesis. The DAT protocol reduced the measurement time by almost half without compromising estimations accuracy or precision. The monotonic protocol was the fastest steady-state method. Estimations of biochemical limitations to photosynthe..., Photosynthetic gas exchange was measured with portable infrared gas analyzer (LI-6800, LI-COR, Lincoln, NE, USA) on fully developed leaves. Chamber conditions were set to mimic species growing conditions (Specific conditions outlined in Table S2). To increase battery life in these field measurements, temperature was controlled at the block level. Across all species, our measurements spanned from 20 – 30 °C and 1000 – 1500 μmol photons m-2 s-1. While we understand that these light intensities are likely slightly sub-saturating, we selected them to minimize the confounding effects of long-term build-up of non-photochemical quenching resulting from the longer total measuring times required to test all the regimes on the same leaf. Leaves were acclimated to this saturating light intensity for at least 5 minutes to ensure rubisco activation before the measurement commenced.
We used 10 biological reps in tobacco to fine-tune the different protocols. We then used 6 biological replicates for al..., We used R Statistical Software for all statistical analyses based on code developed by Mauricio Tejera-Nieves available at https://github.com/PerennialDr/ACi Methods
Please direct correspondence to Berkley Walker (berkely@msu), # The Dynamic Assimilation Technique measures photosynthetic CO2 response curves with similar fidelity as steady-state approaches in half the time

Dataset compiles net CO2 assimilation (A) measurements measured at different internal CO2 concentrations (Ci) using different CO2 protocols (i.e., different sequences of CO2). The aim of the study was to evaluate whether the different CO2 protocols had any impact on the A – Ci response curve.
Each CO2 regime was measured in 5 species: Apple, Arabidopsis, Potato, Soybean and Tobacco. For each plant, all 5 protocols were performed on the same leaf in a randomized order on 10 biological reps for tobacco and 6 for all other species.

## Description of the data and file structure

Data are presented in a long format. Each row corresponds to a net CO2 assimilation observation at a given internal CO2 concentration (Ci), for a given CO2 regime and a given replicate. Columns represent:
Species: Name of the species used in the experiment (one of Appl...

净CO₂同化速率（A）对胞间CO₂浓度（Ci）的响应是光合作用与植物生理学研究中的基础性测量手段。传统A/Ci测量方案依赖稳态测量，单次测量耗时15~40分钟，这限制了数据分辨率与生物学重复数量。此外，现有文献中存在多种CO₂测量方案，但尚未就最优方案达成共识，也未明确不同方案的估计系统偏差。本研究对比了非稳态动态同化技术（Dynamic Assimilation Technique, DAT）方案与三种最常用的稳态CO₂测量方案，并检验了不同CO₂方案是否会导致光合作用生化限制估计的系统性差异。结果显示，动态同化技术可将测量时长缩短近一半，且不会降低估计的准确性与精密度；单调方案是最快的稳态测量方法。光合作用生化限制的估计……

光合气体交换采用便携式红外气体分析仪（portable infrared gas analyzer, LI-6800, LI-COR，美国内布拉斯加州林肯市）在完全展开的叶片上进行测量。气室条件设置为模拟物种原生生长环境（具体条件见补充表S2）。为延长野外测量的电池续航时间，采用模块级温度控制。所有物种的测量温度范围为20~30℃，光强范围为1000~1500 μmol photons m⁻² s⁻¹。尽管我们意识到该光强可能略低于饱和光强，但选择该范围旨在最小化因单叶多方案测试所需总测量时长较长而引发的非光化学淬灭长期积累带来的混杂效应。测量开始前，需将叶片在该光强下适应至少5分钟，以确保核酮糖-1,5-二磷酸羧化酶/加氧酶（Rubisco）完全激活。

本研究使用10个烟草生物学重复对不同测量方案进行微调，随后针对其余物种使用6个生物学重复。所有统计分析均采用R统计软件（R Statistical Software），分析代码由Mauricio Tejera-Nieves开发，可在https://github.com/PerennialDr/ACi Methods获取。通讯作者为Berkley Walker（邮箱：berkely@msu）。**动态同化技术可在减半时长内实现与稳态方法相当的CO₂响应曲线测量保真度**。

本数据集整合了采用不同CO₂方案（即不同CO₂浓度序列）、在不同胞间CO₂浓度下测得的净CO₂同化速率（A）数据。本研究的目的为评估不同CO₂方案是否会对A-Ci响应曲线产生影响。

所有5个物种（苹果、拟南芥、马铃薯、大豆与烟草）均完成了各CO₂方案的测量。对于每株植株，5种方案均以随机顺序在同一片叶片上开展测定：烟草设置10个生物学重复，其余物种设置6个生物学重复。

## 数据与文件结构说明
数据以长格式存储。每一行对应给定CO₂方案与生物学重复下，特定胞间CO₂浓度下的净CO₂同化速率观测值。各列含义如下：
Species：实验所用物种名称（可选值为Appl……）