School of Agriculture, Department of Agriculture, University of Ioannina, Kostakii, 47100, Arta, Greece.
Crop Soil and Environmental Sciences, University of Arkansas, Fayetteville, AR, 72704, USA.
Sci Rep. 2023 Aug 12;13(1):13156. doi: 10.1038/s41598-023-40453-6.
The evolution of secondary sex-specific traits of dioecious species under abiotic stress conditions has received limited research, especially in the case of Amaranthus palmeri, a fast adapting and highly competing plant. Here, we have examined the interactive effects of abiotic stress on mineral accumulation, chlorophyll a and b content, and the operating capacity of Photosystem II (PSII) in both male and female A. palmeri plants grown under three different intensities of white light, and under N, K or P deficiency. Mineral profiling of the leaves and stems (with inflorescence) highlighted intra- and intersexual differences in their accumulation pattern and mineral associations. Chlorophyll a and chlorophyll b were different between the male and the female plants, being slightly lower in the latter, at high light intensity towards maturity, or under K or P deficiency. Further, slight, although statistically significant differences were recorded in the chlorophyll a/b ratio, which was lower at the higher light intensity in the female, over that in the male, plants towards maturity. Chlorophyll fluorescence parameters, i.e., steady state and maximum fluorescence increased under high light intensity, whereas the PSII operating efficiency decreased in the female plants, indicating reduced PSII capacity. Sex-specific differences in A. palmeri showed a differential response to stressful conditions because of differences in their ontogeny and physiology, and possibly due to the cost of reproduction. We suggest that the breeding system of dioecious species has weaknesses that can be used for the ecological management of dioecious weeds without relying on the use of herbicides.
雌雄异株物种在非生物胁迫条件下的次生性别特异性特征的进化受到的研究较少，尤其是在适应能力强且竞争力强的植物 Palmer 猪毛菜（Amaranthus palmeri）的情况下。在这里，我们研究了非生物胁迫对矿物质积累、叶绿素 a 和 b 含量以及在三种不同白光强度和 N、K 或 P 缺乏条件下生长的雄性和雌性 Palmer 猪毛菜植物中 PSII 操作能力的相互作用影响。叶片和茎（含花序）的矿物质分析突出了它们在积累模式和矿物质结合方面的雌雄间差异。叶绿素 a 和叶绿素 b 在雄性和雌性植物之间存在差异，在高光强下成熟时或在 K 或 P 缺乏时，后者的含量略低。此外，在高光强下，雌性植物的叶绿素 a/b 比值略低，但统计上有显著差异，表明雌性植物的 PSII 能力降低。叶绿素荧光参数，即稳态和最大荧光，在高光强下增加，而 PSII 运行效率在雌性植物中降低，表明 PSII 能力降低。Palmer 猪毛菜的性别特异性差异表现出对胁迫条件的不同反应，这是由于它们的个体发育和生理学的差异，以及可能由于繁殖成本的差异。我们认为，雌雄异株物种的繁殖系统存在弱点，可以在不依赖除草剂的情况下用于雌雄异株杂草的生态管理。
