植物的交配方式（自交vs異交）不僅影響植物自身雌,、雄配子結(jié)合以及形成合子的方式，還決定了植物群體未來世代的基因型頻率,、植物的有效群體大小,、基因流、選擇等進(jìn)化因素,，然而對于從更深層面揭示植物不同交配系統(tǒng)產(chǎn)生的進(jìn)化后果,，目前的研究卻涉及較少。
近日,，康奈爾大學(xué)生態(tài)與進(jìn)化生物學(xué)系A(chǔ)ndré Kessler博士與Stuart A. Campbell博士從新的角度研究植物交配系統(tǒng)轉(zhuǎn)變對植物防御機(jī)制進(jìn)化的影響,，并取得了階段性成果，其研究論文Plant mating system transitions drive the macroevolution of defense strategies在美國國家科學(xué)院院刊（PNAS）上發(fā)表,。該論文以分別具有自交親和（Self-Compatibility,，SC）與自交不親和的（Self–Incompatibility，SI）的茄科13屬共56種植物為研究材料,，探討具有不同交配系統(tǒng)的茄科植物與昆蟲煙草天蛾（以捕食茄科植物葉片為主）的互作及防御機(jī)制,。結(jié)果顯示伴隨著植物交配方式從自交不親和系統(tǒng)（SI）向自交親和系統(tǒng)（SC）單向、多次發(fā)生的轉(zhuǎn)變,，茄科植物對昆蟲的誘導(dǎo)性防御方式增加，并且植物對昆蟲的誘導(dǎo)性防御?；栽鰪?。
從進(jìn)化角度來看，自交不親和系統(tǒng)在植物長期進(jìn)化過程中有利于異花授粉和保持植物高度雜合性,，具有較高的進(jìn)化優(yōu)勢,。在茄科植物與昆蟲的互作與協(xié)同進(jìn)化中，植物從自交不親和向自交親和系統(tǒng)的轉(zhuǎn)變可能是植物在進(jìn)化過程中從組成型防御向誘導(dǎo)性防御轉(zhuǎn)變的代償機(jī)制,。（生物谷Bioon.com）
doi:10.1073/pnas.1213867110
Plant mating system transitions drive the macroevolution of defense strategies
Stuart A. Campbell1 and André Kessler
Understanding the factors that shape macroevolutionary patterns in functional traits is a central goal of evolutionary biology. Alternative strategies of sexual reproduction (inbreeding vs. outcrossing) have divergent effects on population genetic structure and could thereby broadly influence trait evolution. However, the broader evolutionary consequences of mating system transitions remain poorly understood, with the exception of traits related to reproduction itself (e.g., pollination). Across a phylogeny of 56 wild species of Solanaceae (nightshades), we show here that the repeated, unidirectional transition from ancestral self-incompatibility (obligate outcrossing) to self-compatibility (increased inbreeding) leads to the evolution of an inducible (vs. constitutive) strategy of plant resistance to herbivores. We demonstrate that inducible and constitutive defense strategies represent evolutionary alternatives and that the magnitude of the resulting macroevolutionary tradeoff is dependent on the mating system. Loss of self-incompatibility is also associated with the evolution of increased specificity in induced plant resistance. We conclude that the evolution of sexual reproductive variation may have profound effects on plant–herbivore interactions, suggesting a new hypothesis for the evolution of two primary strategies of plant defense.
