薇甘菊（Mikania micrantha）是一种快速生长的全球性入侵杂草，广泛分布在热带和亚热带地区。薇甘菊的入侵会对当地自然生态系统造成严重破坏，并对森林和作物生产造成巨大的经济损失。它在光合作用方面具有优势，其净光合速率与C₄植物相近，固碳能力较高。研究表明薇甘菊的光合能力是其快速生长和快速殖民新栖息地的重要原因之一。然而，目前尚没有研究揭示薇甘菊光合作用的进化机制和昼夜规律。本研究采用基因组学和转录组学相结合的方法，揭示了薇甘菊光合作用的进化机制和昼夜表达模式。结果显示，在薇甘菊中有16个正选择基因，主要集中于光反应和光同化物的利用两个过程中，并且叶绿素a/b结合蛋白、苹果酸脱氢酶、丙酮酸正磷酸二激酶和苹果酸酶家族的基因数量与C₄植物(高粱或玉米)相似，显著高于其他植物。在不同组织中，98.1%与光反应相关的基因在茎中具有较高表达，C₄循环相关的基因中有一半以上在茎中高于叶中的表达。气孔开闭过程中，2个碳酸酐酶基因在18:00的表达量高于8:00，SLAC1和HT1基因在18:00表达量最低。此外，与光合作用相关的基因在7:00和17:00表达量较高。因此我们推测，薇甘菊能够在茎和花器官中进行光合作用，并且叶片的一些气孔在夜间能够通过CO₂信号打开。此外，它的进化可能会减弱高光强时的光抑制，并在低光强时提高光合作用的效率。组织特异性光合类型和光合相关基因的不同昼夜模式可能有助于薇甘菊在新栖息地的快速定植。薇甘菊可能通过这些变化增加了它的种间优势和侵袭性。本文的研究结果为了解薇甘菊的光合作用机制及其控制和生物利用度提供了有价值的信息。

Melatonin is a naturally occurring compound in plants.  Here, we tested the effect of exogenous melatonin on rapeseed (Brassica napus L.) grown under salt stress.  Application of 30 μmol L^–1 melatonin alleviated salt-induced growth inhibition, and the shoot fresh weight, the shoot dry weight, the root fresh weight, and the root dry weight of seedlings treated with exogenous melatonin increased by 128.2, 142.9, 122.2, and 124.2%, respectively, compared to those under salt stress.  In addition, several physiological parameters were evaluated.  The activities of antioxidant enzymes including peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) were enhanced by 16.5, 19.3, and 14.2% compared to their activities in plants without exogenous melatonin application under salt stress, while the H₂O₂ content was decreased by 11.2% by exogenous melatonin.  Furthermore, melatonin treatment promoted solute accumulation by increasing the contents of proline (26.8%), soluble sugars (15.1%) and proteins (58.8%).  The results also suggested that higher concentrations (>50 μmol L^–1) of melatonin could attenuate or even prevent the beneficial effects on seedling development.  In conclusion, application of a low concentration of exogenous melatonin to rapeseed plants under salt stress can improve the H₂O₂-scavenging capacity by enhancing the activities of antioxidant enzymes such as POD, CAT and APX, and can also alleviate osmotic stress by promoting the accumulation of osmoregulatory substances such as soluble proteins, proline, and water soluble glucan.  Ultimately, exogenous melatonin facilitates root development and improves the biomass of rapeseed seedlings grown under salt stress, thereby effectively alleviating the damage of salt stress in rapeseed seedlings.

Morphology and morphometry of six biotypes (B, Q, Cv, ZHJ-1, ZHJ-2 and ZHJ-3) of Bemisia tabaci (Gennadius) from China on cotton plants were studied by using microscopes. Nymphal body sizes and characters were measured and observed, especially on the 4th instar (pupal case), including the vasiform orifice, operculum, lingula, length and thickness of anterior and posterior wax margins, width of thoracic tracheal combs. Adult characters of both sexes were investigated including the body size, compound eyes, antennal segments, vasiform orifice, hind tarsi and genitals. The results indicated that differences of some morphological characters or morphometrics were significant among the six biotypes of B. tabaci in China: (1) Pupal sizes of the exotic biotypes (B and Q) were significantly larger than the indigenous biotypes with the following order as B>Q>ZHJ-1>Cv>ZHJ-3>ZHJ-2; (2) for both male and female adults, sizes of all characters investigated in the invading biotypes (B and Q), especially B, were much larger than those of the indigenous ones.