Gender-related responses of dioecious plant Populus cathayana to AMF, drought and planting pattern

Abstract

in our previous studies, we detected drought, gender and arbuscular mycorrhizal (AM) inoculation effects on dioecious plant. Based on this, we investigated the intra-and inter-sexual competition between male and female plants. Dioecious plant Populus cathayana was used and we set 3 factors in this experiment: (1) AM inoculation/non-inoculation; (2) well-watered/water-stressed; (3) singlegender pattern (only 4 males or 4 females)/mixed-gender pattern (2 males and 2 females). Growth (stem length, ground diameter, SPAD, mean leaf area, biomass accumulation) and nutrition (C, N, P, K, Ca and Mg) distribution of male and female seedlings were determined. Results Drought significantly limited plant growth and nutrition accumulation, especially in female plants; AM formation alleviated this negative effect, especially in male plants. However, the gender effect was complicated. A mixedgender planting pattern relieved intra-competition in terms of the growth and nutrient accumulation of both genders and even alleviated the negative effects caused by drought. In the mixed-gender pattern, the differences of C, N, P, K and Ca contents between male and female plants with AM inoculation was smaller than those without AM inoculation, which indicated a potential role for AM fungi in nutrient transport. Males had a stronger physiological response to limited water availability, and more advantages from AM formation than females. Mixed-gender planting relieved the existence of intra-sexual competition of dioecious plants, and AM symbiosis alleviated the differences between genders. Forests cover 30% of the world's land surface and are relied on by human societies. However, land use by our expanding human population and economic decisions are rapidly and directly transforming forested ecosystems 1. With increasingly higher global temperature, which is now widely acknowledged because of increasing emissions of greenhouse gases, significant drying is occurring widely around the world 2,3. The impacts of climate change have both positive and negative sides. However, increases in water use efficiency, growth from higher CO 2 levels, and the growing season suggest positive effects of future climate change on forests. The changing climate induces stress and changes the dynamics of forest insects and pathogens, which reduce tree growth and increase mortality 4,5. Afforestation is a well-accepted method for ecological restoration in arid areas 6 , and poplar is a widely cultivated forest tree with high economic value, especially in the energy and papermaking industries 7,8. Populus cathayana, a typical dioecious plant, is an ecologically important species in Qinghai Province, China, a severely ecologically degraded area. Despite decades of studies within the fields of forestry, plant pathology and entomology, the fundamental mechanisms of tree survival and mortality during drought remain poorly understood 9-11. Most terrestrial plants can establish symbiosis with arbuscular mycorrhizal (AM) fungi, which is widespread, and has been suggested...

Sexual Dimorphism in the Chemical Composition of Male and Female in the Dioecious Tree, Juniperus communis L., Growing under Different Nutritional Conditions

“…Stress conditions (e.g., drought, nutrient deficiency) can affect allocation strategies differently in males and females [21]. The depletion of nutrients stored in stems can have a more severe effect on reproduction in females than in males [9].…”

Impact of salt and exogenous AM inoculation on indigenous microbial community structure in the rhizosphere of dioecious plant, Populus cathayana

“…In our study, the formation of AM symbiosis changed certain physical–chemical properties of the rhizosphere soil, which differed between host genders 29 . Many studies have shown sex-specific response mechanisms under various kinds of abiotic stresses 30 , which may have resulted in the sex-specific microbial environments of P. cathayana . Thus, the sex-specific effects of AM on the microbial community of dioecious P. cathayana may be due to the sex-specific root exudate composition, root environment, and colonization status 31 – 33 .…”

Defence Is a Priority in Female Juveniles and Adults of Taxus baccata L.

“…SSD can also be affected by habitat conditions; furthermore, in many cases, differences between sexes are present only under stressful conditions [8,18,19]. However, in other studies, female individuals make better use of available resources under fertile conditions [20,21].…”

“…Moreover, vegetative reproduction is a common phenomenon, and 66.5% of species of central European plants exhibited clonal growth [30]. Cuttings have been used in a number of SSD research studies (e.g., [19,[31][32][33]).…”