Plasticity of female reproductive resource allocation depends on the presence or absence of prior environmental sex determination in Ceratopteris richardii

Abstract

Resource allocation plasticity enables individuals to alter patterns of nutrient use between reproductive and vegetative output to better fit their current environment. In sexually labile plant species, abiotic environmental factors can influence expression of dimorphic gender, resulting in environmental sex determination (ESD), which potentially reduces the need for plasticity of resource allocation by preemptively matching an individual’s future nutrient demands to resource availability in its location. Ceratopteris richardii gametophytes exhibit gender‐dependent differences in relative carbon and nitrogen content, and ESD in certain nutrient environments. This study examined whether prior ESD in C. richardii gametophyte populations reduced subsequent plasticity of reproductive allocation compared to instances where no ESD occurred, by quantifying phenotypic responses to reduced P, N, or CO 2 availabilities. All three nutrient‐limited environments resulted in decreased size of egg‐bearing (meristic) gametophytes compared to nonlimited environments, but gametophytes failed to respond to N and CO 2 limitation at the time of sex determination, resulting in no ESD. N limitation resulted in a predictable allometric re‐allocation of resources based on small gametophyte size, whereas CO 2 limitation caused a change in reproductive output consistent with true plasticity. Withholding exogenous P caused ESD and had no effect on relative reproductive output of resultant meristic gametophytes because the size decrease was minor. Under P limitation, ESD matched the resource demands of gender phenotypes to their environment before the onset of developmental dimorphism, reducing the need for large allocation adjustments after sex determination.

Nutrition regulates sex expression in a gender diphasy plant, Lilium concolor var. megalanthum

“…megalanthum considered the dual needs of belowground root space expansion and aboveground leaves to obtain light energy resources, and promoted the simultaneous growth of aboveground and belowground parts ( Bai et al., 2020 ). In addition, the response of plants to the potential limitation of essential nutrients makes them reallocate resources based on the trade-off of important organ resource demand ( Goodnoe and Hill, 2018 ). When the content of nitrogen and phosphorus in the soil was low (potassium addition treatment), the Lilium concolor var.…”

“…Variability of sex expression is a key survival strategy in the life history of a few plants. Studies have shown that the reproductive success of sessile plants depends heavily on their ability to respond to environmental changes ( Goodnoe and Hill, 2018 ). If plants can choose more effective sexual functions according to environmental changes and can change sex expression with environmental changes, then this sexual strategy is the most adaptive ( Zhang et al., 2014 ; Niu et al., 2017 ; Blake-Mahmud and Struwe, 2019 ).…”

“…The response of plants to environmental changes and the potential limitation of essential nutrients makes them allocate resources among important functions ( Sardans and Peñuelas, 2015 ; Goodnoe and Hill, 2018 ). Any mismatch of resources will affect plant development ( Fairhurst et al., 2022 ).…”