Exploring the influences of resource limitation and plant aging on pollen development in Azorella nivalis Phil. (Apiaceae), a long‐lived high‐Andean cushion plant

STRELIN, M. M.; GAVINI, S. S.; SOARES, N. C.; CHALCOFF, V. R.; AIZEN, M. A.; ZATTARA, E. E.; GLEISER, G. L.

PLANT BIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2025 vol. 27 p. 154 - 162

1435-8603

Angiosperm pollen, the male gametophyte, plays a crucial role in facilitating fertilizationby protecting and transporting male sperm cells to the female pistil. Despite theirseemingly simple structure, pollen grains undergo intricate development to produceviable sperm cells capable of fertilizing the egg cell. Factors such as resource limitationand plant aging can disrupt normal pollen development and affect pollen performance.We investigated the influence of plant resources and aging on pollen developmentalfailure in Azorella nivalis Phil., an exceptionally long-lived high-Andeanspecies that grows in a stressful alpine environment. Leveraging the modular nature ofplants, we aimed to identify intra-individual sources of variation in pollen developmentalfailure.By using pollen viability and variation in viable pollen grain size as indicators of pollendevelopmental performance, we assessed whether proxies of plant resource availabilityand aging influenced these pollen traits at the inter-individual, inter-flower and intraflowerlevels.Our findings revealed decreased pollen viability in putative resource-depleted flowersand in shoots that experienced higher levels of meristematic divisions from the zygote(i.e., greater cell depth). Additionally, we observed increased variability in the size ofviable pollen grains in resource-depleted anthers.Our study suggests that resource availability and shoot aging are critical determinantsshaping pollen development in long-lived plants at the intra-individual level. Thesefindings contribute to our understanding of how differences in male fitness can arisein plants, with implications for their evolutionary trajectory.