Foliar nutrient allocation patterns in Banksia attenuata and Banksia sessilis differing in growth rate and adaptation to low-phosphorus habitats

Abstract

Background and aims Phosphorus (P) and nitrogen (N) are essential nutrients that frequently limit primary productivity in terrestrial ecosystems. Efficient use of these nutrients is important for plants growing in nutrient-poor environments. Plants generally reduce foliar P concentration in response to low soil P availability. We aimed to assess ecophysiological mechanisms and adaptive strategies for efficient use of P in Banksia attenuata (Proteaceae), naturally occurring on deep sand, and B. sessilis, occurring on shallow sand over laterite or limestone, by comparing allocation of P among foliar P fractions. Methods We carried out pot experiments with slow-growing B. attenuata, which resprouts after fire, and faster-growing opportunistic B. sessilis, which is killed by fire, on substrates with different P availability using a randomised complete block design. We measured leaf P and N concentrations, photosynthesis, leaf mass per area, relative growth rate, and P allocated to major biochemical fractions in B. attenuata and B. sessilis. Key results The two species had similarly low foliar total P concentrations, but distinct patterns of P allocation to P-containing fractions. The foliar total N concentration of B. sessilis was greater than that of B. attenuata on all substrates. The foliar total P and N concentrations in both species decreased with decreasing P availability. The relative growth rate of both species was positively correlated with concentrations of both foliar nucleic acid P and total N, but there was no correlation with other P fractions. Faster-growing B. sessilis allocated more P to nucleic acids than B. attenuata did, but other fractions were similar. Conclusions The nutrient-allocation patterns in faster-growing opportunistic B. sessilis and slower-growing B. attenuata revealed different strategies in response to soil P availability which matched their contrasting growth strategy.

Foliar P-Fractions Allocation of Karelinia caspia and Tamarix ramosissima Are Driven by Soil and Groundwater Properties in a Hyper-Arid Desert Ecosystem

“…Compared with the leaf P content in the two species, the leaf N content of T. ramosissima was higher than K. caspica . These findings differs from results on Hakea prostrata (Proteaceae) which showed that P availability does not affect leaf N content ( Prodhan et al, 2019 ), but correlated leaf N and leaf P content was similar, and enhanced as increasing soil available-P concentration or groundwater available-P concentration ( Han et al, 2021 ). The leaf N content of both species was lower than both those in global soils ( Cleveland and Liptzin, 2007 ; Xu et al, 2013 ), and lower than results previously reported on A. sparsifolia in this area ( Zhang et al, 2018 ; Gao et al, 2022 ).…”

“…This is consistent with results from this study where T. ramosissima growth was more likely limited by P while K. caspica growth was not. In addition, the higher leaf N content and leaf N:P ratios suggest that more leaf P was allocated to nucleic acid-P ( Figure 4 ; Han et al, 2021 ). Interestingly, however, the ratios of leaf N:P Fraction in each P fraction, with the exception of residual-P, were higher in T. ramosissima than in K. caspica ( Table 3 ).…”

“…In P-impoverished soils, A. sparsifolia reduced the metabolites-P content but increased the nucleic acid-P content. In addition, foliar-P fractions allocation may be related to life history because these fractions are functionally associated with growth and reproduction ( Hidaka and Kitayama, 2011 ; Han et al, 2021 ). For example, Han et al (2021) found that faster-growing tree species allocate more foliar-P to nucleic acid-P than slow-growing tree species.…”

“…In addition, foliar-P fractions allocation may be related to life history because these fractions are functionally associated with growth and reproduction ( Hidaka and Kitayama, 2011 ; Han et al, 2021 ). For example, Han et al (2021) found that faster-growing tree species allocate more foliar-P to nucleic acid-P than slow-growing tree species. According to the growth-rate hypothesis (GRH), fast-growing plants need to allocate more foliar-P for protein synthesis and enzyme-related nucleic acid-P (RNA, especially rRNA) to supply photosynthesis and other physiological needs ( Elser and Hamilton, 2007 ; Reef et al, 2010 ; Hidaka and Kitayama, 2011 ).…”

Genetic variation in morphological traits in cotton and their roles in increasing phosphorus-use-efficiency in response to low phosphorus availability

“…Moreover, LP conditions significantly enhanced the R/S ratio in this study ( Supplementary Table S2 ). Previous research found that the increased allocation of photosynthates to roots, which leads to an increased root-to-shoot ratio and P acquisition, was linked to how crop plants responded to P deprivation ( Han et al., 2021 ). In plants with a P shortage, it was found that allocating biomass to root development improves P uptake ( Brown and Linch, 2001 ; Wen et al., 2019 ).…”