The ER-resident molecular chaperone BiP (binding protein) was overexpressed in soybean. When plants growing in soil were exposed to drought (by reducing or completely withholding watering) the wild-type lines showed a large decrease in leaf water potential and leaf wilting, but the leaves in the transgenic lines did not wilt and exhibited only a small decrease in water potential. During exposure to drought the stomata of the transgenic lines did not close as much as in the wild type, and the rates of photosynthesis and transpiration became less inhibited than in the wild type. These parameters of drought resistance in the BiP overexpressing lines were not associated with a higher level of the osmolytes proline, sucrose, and glucose. It was also not associated with the typical drought-induced increase in root dry weight. Rather, at the end of the drought period, the BiP overexpressing lines had a lower level of the osmolytes and root weight than the wild type. The mRNA abundance of several typical drought-induced genes [NAC2, a seed maturation protein (SMP), a glutathione-S-transferase (GST), antiquitin, and protein disulphide isomerase 3 (PDI-3)] increased in the drought-stressed wild-type plants. Compared with the wild type, the increase in mRNA abundance of these genes was less (in some genes much less) in the BiP overexpressing lines that were exposed to drought. The effect of drought on leaf senescence was investigated in soybean and tobacco. It had previously been reported that tobacco BiP overexpression or repression reduced or accentuated the effects of drought. BiP overexpressing tobacco and soybean showed delayed leaf senescence during drought. BiP antisense tobacco plants, conversely, showed advanced leaf senescence. It is concluded that BiP overexpression confers resistance to drought, through an as yet unknown mechanism that is related to ER functioning. The delay in leaf senescence by BiP overexpression might relate to the absence of the response to drought.

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h i g h l i g h t s " Two soybean genotypes with low and normal linolenic acid content as sources of raw material for biodiesel production. " Evaluation of the soybean characteristics, and main biodiesel properties. " Biodiesel of the low linolenic soybean presented good properties.

Leaf lipoxygenases (LOX) are involved with important physiological processes such as plant growth and development, senescence, biosynthesis of regulatory molecules, and response to pathogens and insects. We did a biochemical evaluation of the LOX pathway of soybean leaves submitted to wounding in a normal genotype (IAC-100) and its counterpart lacking seed LOX (IAC-100 TN). Our results indicate that LOX activities in the different pHs and temperatures tended to be higher in the wounded plants compared to their respective controls. The K M app values at 168 h after wounding reached a minimum in both genotypes indicating that the plants respond by changing the leaf LOX pool. There was an increase on protease inhibitor levels in all time points after wounding, for both cultivars. The levels of hexanal and total aldehydes are similar for the wounded plants at different times after wounding and their respective controls for both genotypes. Our results strongly suggest that the LOX pathway is activated during the wound response leading to jasmonate by the initial action of hydroperoxide cyclase. In addition, the results show that the genetic removal of seed LOX does not interfere with the plant’s ability to respond to wound via the LOX pathway.