小麦抗旱相关基因TaPYL4的功能分析及标记开发

随着我国Bt作物种植面积的增加，绿盲蝽和其他盲蝽逐渐成为重要农业害虫因为它们对作物中的Bt蛋白不敏感。此外，Bt作物种植后杀虫剂使用量的减少也增加了盲蝽爆发的严重程度。红颈常室茧蜂是一种盲蝽若虫的寄生蜂，但它对Bt蛋白的敏感性尚不清楚。在当前研究中，我们利用添加Bt蛋白（400 µg g^-1）或不添加Bt蛋白的10%蜂蜜水，发展了一种评价Bt蛋白（Cry1Ab, Cry1Ac, Cry1F, Cry2Aa和Cry2Ab）对红颈常室茧蜂成虫影响的直接暴露试验体系。结果显示，红颈常室茧蜂成虫的存活和繁殖情况能够被半胱氨酸蛋白酶抑制剂E-64（阳性对照）显著抑制，但不受供试5种Bt蛋白影响。此外，寄生蜂体内的消化酶、解毒酶和保护酶活性也不受供试Bt蛋白影响，但取食含E-64的饲料后，它们受到显著影响。然后我们建立了一种三级营养试验，来测定供试5种Bt蛋白对红颈常室茧蜂幼虫和蛹的影响，在这个试验中，以取食含有Cry蛋白饲料的盲蝽若虫作为红颈常室茧蜂的寄主昆虫。三级营养试验的结果显示，即使被寄主的绿盲蝽体内含有大量Bt蛋白，以它们为寄主的红颈常室茧蜂寄生蜂化蛹率和羽化率也没有受到显著影响。上述结果整体表明，研究中发展的这2个生物试验可以用来评价杀虫物质对红颈常室茧蜂的毒性，供试的Cry蛋白对红颈常室茧蜂无毒性。

Wheat crown rot caused by Fusarium spp. is a common disease worldwide.  Both Fusarium pseudograminearum and Fusarium graminearum infect wheat crown and produce mycotoxin leading to grain loss due to white head.  F. pseudograminearum (Fp) was reported in wheat from Henan Province of China a couple of years ago.  The wheat crown rot (CR) caused by this new pathogen is as an emerging severe disease of wheat, which has recently expanded to several provinces in China and is, therefore, under rapid investigation.  Colonization of wheat tissue by Fp is accomplished though the formation of a septated foot-shaped appressoria and generation of a penetration peg to break through the internal cells of leaf sheath.  The molecular mechanism by which Fp regulates the pathogenesis on wheat host is unclear.  Here, we report FpPDE1, a P-type ATPase-encoding predicted PDE1 orthologue gene of Magnaporthe oryzae, belonging to the DRS2 subfamily of aminophospholipid translocases.  The gene deletion of FpPDE1 with the split-marker approach did not obviously affect hyphae growth and conidiation, but led to an attenuated virulence on wheat base stem and root.  Our finding indicates that the putative aminophospholipid translocases is not essential for the infectious hyphae development in Fp.  

Nitric oxide (NO) is a gaseous signaling molecule in plants that plays a key role in mediating a wide range of physiological processes and responses to biotic and abiotic stresses. The present study was conducted to investigate the effects of the exogenous application of sodium nitroprusside (SNP), an NO donor, on cadmium (Cd)-induced oxidative stress and Cd uptake in rice plants. Rice plants were exposed to Cd stress (0.2 mmol L-1 CdCl2) and different concentrations of SNP (0.05, 0.1, 0.2, and 0.4 mmol L-1). A SNP concentration of 0.1 mmol L-1 (SNP10) significantly reduced the Cd-induced decrease in shoot and root dry weights and leaf chlorophyll concentrations. The addition of NO also reduced the malondialdehyde (MDA), hydrogen peroxide (H2O2) and ascorbic acid (ASA) concentrations. However, the reduction in glutathione (GSH) concentration was inhibited by NO treatment. Moreover, NO prevented the Cd-induced increase in antioxidative enzyme activity. The amount of Cd accumulation in rice plants was also influenced by the addition of NO. The NO supplied by the SNP enhanced the Cd tolerance of the rice by increasing the Cd uptake by the roots and decreasing the Cd accumulation by the shoots. However, the application of potassium ferrocyanide (Cd+Fe) or sodium nitrate and nitrite (Cd+N) (without NO release), did not exhibit the effects of the SNP. Furthermore, the effects of the SNP were reversed by the addition of hemoglobin (an NO scavenger). Our results suggested that exogenous NO was involved in the resistance of rice to Cdtoxicity.